Name: 1004-36-0|2,6-Dimethyl-4H-pyran-4-one|95%
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SKU: A472870
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1
[ 1004-36-0 ]
[ 109-77-3 ]
[ 28286-88-6 ]

Yield	Reaction Conditions	Operation in experiment
72.5%	With acetic anhydride; for 2h;Reflux;	Preparation of compounds of formula (1) (R1, R2 are both H)2,6-dimethyl-4-pyrone (25 mmol, 3.1 g)withMalononitrile (250 mmol, 16.5 g)Added to 15mL of anhydrous acetic anhydride,The reaction mixture was stirred at reflux for 2h.After the reaction was completed, the reaction system was cooled to room temperature, 50 mL of boiling water was added thereto, a large amount of solid was precipitated, suction filtered, and the brown crude product was collected.The crude product was purified by silica gel column chromatography using petroleum ether / ethyl acetate (volume ratio of both: 10: 1) as eluent,The compound of formula (1) was obtained as a yellow solid,Yield 72.5%.
60%	In acetic anhydride; for 5h;Reflux; Inert atmosphere;	2,6-dimethyl-gamma-pyrone (12.50 g, 0.100 mol) and malononitrile (6.90 g, 0.104 mol) were dissolved in 50 mL of acetic anhydride; the solution was refluxed, under nitrogen flux, for 5 h. The system was then slowly cooled down to room temperature and the crystallization of a brown compound occurred. This compound was recovered by suction filtration and recrystallized by chloroform-hexane. Light brown needle-shape crystals were obtained. The yield was 60%. 1H NMR (CDCl3, 200 MHz); delta = 2.31 (s, 6H, -CH3); 6.53 (s, 2H, pyran CH). Mp: 192 C.
60%	With acetic anhydride;Reflux; Inert atmosphere;	2,6-dimethyl-g-pyrone (12.50 g, 0.100 mol) and malononitrile(6.90 g, 0.104 mol) were dissolved in 50 mL of acetic anhydride; thesolution was refluxed, under nitrogen flowing, for 5 h. The systemwas then slowly cooled down to room temperature and the crystallizationof a brown compound occurred. The compound wasrecovered by suction filtration and recrystallized by chloroformhexane.Light brown needle-shape crystals were obtained. Theyield was 60%.1H NMR (CDCl3, 200 MHz); delta 2.31 (s, 6H, -CH3); 6.53 (s, 2H,pyran CH).Mp: 192 C.

57%

With acetic anhydride; for 1.5h;Reflux;

Example 8; Preparation of a compound having the formula:; (a) A 10.00 g sample of 2,6-dimethyl-gamma-pyrone was dissolved in 40 niL of acetic anhydride. To this solution was added 5.3 rnL of malononitrile and the mixture was heated in an oil bath for 90 min at reflux temperature. Using a distillation apparatus, the volume was reduced by one half. The brown solution was added to 600 mL warm H2O, resulting in a dark brown crystalline solid, which was collected by vacuum filtration to yield 7.901 g (57%) (NMR (CDCl3) delta 6.57 (s, 2, pyrone), 2.32 (s, 6, CH3.)) of a compound having the formula:.

Reference： [1]Macromolecules,2005,vol. 38,p. 6336 - 6345
[2]RSC Advances,2015,vol. 5,p. 20712 - 20715
[3]Advanced Functional Materials,2012,vol. 22,p. 771 - 779
[4]Patent: CN104356055,2016,B .Location in patent: Paragraph 0057-0059
[5]Journal of Physical Chemistry A,2011,vol. 115,p. 2830 - 2836
[6]Chinese Journal of Chemistry,2011,vol. 29,p. 1951 - 1954
[7]New Journal of Chemistry,2017,vol. 41,p. 3790 - 3797
[8]Journal of Photochemistry and Photobiology A: Chemistry,2016,vol. 321,p. 79 - 89
[9]Dyes and Pigments,2016,vol. 133,p. 395 - 405
[10]Patent: WO2010/54183,2010,A2 .Location in patent: Page/Page column 49-50
[11]Chemistry - An Asian Journal,2017,vol. 12,p. 1374 - 1380
[12]Journal of the American Chemical Society,1958,vol. 80,p. 1440
[13]Tetrahedron,2008,vol. 64,p. 3772 - 3781
[14]Journal of Materials Chemistry,2011,vol. 21,p. 3768 - 3774
[15]Dyes and Pigments,2016,vol. 133,p. 261 - 272
[16]Journal of Materials Chemistry B,2016,vol. 4,p. 4683 - 4689
[17]Dyes and Pigments,2017,vol. 141,p. 428 - 440
[18]Journal of Organometallic Chemistry,2017,vol. 846,p. 397 - 406
[19]Journal of Materials Chemistry C,2017,vol. 5,p. 5183 - 5192
[20]Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy,2019,vol. 214,p. 469 - 475

2
[ 1004-36-0 ]
[ 1073-79-6 ]

Yield	Reaction Conditions	Operation in experiment
	With hydrogen;palladium 10% on activated carbon; In ethanol; at 20℃; under 760.051 Torr; for 25h;	Example 9-1 2,6-Dimethyltetrahydro-4H-pyran-4-one 2,6-Dimethyl-4H-pyran-4-one (4g) was dissolved in ethanol (20mL) and 10% Pd/C (400mg) was added. The mixture was hydrogenated under H2 (latm) at room temperature for 25hrs. The catalyst was filtered through a celite pad and washed with ethanol. The filtrate was concentrated in vacuo, and the residue was purified with silica gel chromatography (hexane/ethyl acetate = 4/1) to give the target compound as a colorless oil (2. 08g). 1H-NMR (300MHz, CDC13) : 6 1. 33 (3H, d, J=6. 0Hz), 2.22 (1H, dd, J=11.4, 14.4Hz), 2.36 (1H, dd, J=2. 7,14. 4Hz), 3.74 (1H, ddq, J=2.7, 6.0, 11.4Hz).
5.1 g	With palladium on activated charcoal; hydrogen; In tetrahydrofuran; at 50℃; under 760.051 Torr; for 22h;	At 50 C, a solution of 2,6-dimethyl-4H-pyran-4-one (6.21 g, 50.0 mmol) in THF (93 mL) was treated with palladium on charcoal (0.53 g, 0.50 mmol). The mixture was put under H2 (1 atm), stirred for 22 h at 50 C, cooled to r.t., filtered25 (Celite) and evaporated to leave an oil (9 g). Flash chromatography (40g Si cartridge,10% TBME in petrol ether) afforded a yellow oil (5.1 g). ?H NMR (400 MHz, CDC13)oe ppm 1.30 (6H, d), 2.16 (2H, dd), 2.31 (2H, dd), 3.68 - 3.76 (2H, m). ?3C NMR (100MHz, CDC13) oe ppm 22.2 (CH3), 49.2 (CH2), 73.2 (OCH), 218.0 (CO).

Reference： [1]Chemische Berichte,1915,vol. 48,p. 684
[2]Chemische Berichte,1923,vol. 56,p. 2012
[3]Patent: WO2005/42533,2005,A2 .Location in patent: Page/Page column 61
[4]Patent: WO2016/55858,2016,A1 .Location in patent: Page/Page column 155; 156

3
[ 1004-36-0 ]
[ 752244-29-4 ]

Yield	Reaction Conditions	Operation in experiment
61%	With hydrogen;palladium 10% on activated carbon; In ethanol; under 2327.23 Torr; for 8h;	A mixture of ketone 58A {13.0 g), Pd/C (10%) (1.5 g) in EtOH (80 mL) was reacted in a hydrogenation vessel under 45 psi for 8 hours. Then the mixture was filtered through Celite <n="194"/>and concentrated in vacuo. The residue was purified on a silica gel column (ISCO) with EtOAc in hexanes (0->25%) to provide 58B (8.0 g, 61% yield).
	With hydrogen;palladium 10% on activated carbon; In ethanol; under 1520.1 Torr; for 2h;	[00307] Intermediate X13 was prepared from commercially available 2,6-dimethyl-g- pyrone (Aldrich Chemical Co., Milwaukee, Wisconsin, USA). A solution of the g-pyrone was dissolved in EtOH and hydrogenated (2 atm. H2) with 10% Pd/C over 2h. The catalyst was subsequently filtered off and the solution was concentrated in vacuo to yield crude X13 which was purified by column chromatography to yield pure compound X13. 1H-NMR (CDCl3, 500 MHz): 3.72 (m, 2H), 2.35 (m, 2H), 2.21 (dd, 2H), 1.32 (d, 6H) ppm.
		A solution of 2,6-dimethyl-4H-pyran-4-one (2 g, 16.1 mmol) in EtOH (20 mL) was stirred over Pd/C (10 wt.%, 0.2 g) under hydrogen (15 psi) for 16 hrs at ambient temperature. The suspension was filtered off and the filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane (15 mL) and treated with Dess-Martin periodinane (2.3 g) at ambient temperature for 16 hrs. To the suspension was added saturated aqueous sodium thiosulfate solution (~3 mL) and the mixture was stirred for 1 hr. The mixture was diluted with saturated aqueous sodium bicarbonate solution (20 mL) and stirred for an additional 1 hr. The separated organic phase was washed with water and brine, dried over sodium sulfate, filtered through celite and concentrated under reduced pressure. The residue was purified by column chromatography [silica gel, EtO Ac/heptane = 10/90]. Fractions were combined and concentrated under reduced pressure providing (2R,6S)-2,6-dimethyldihydro-2H-pyran-4(3H)-one (600 mg). GCMS: 128 [M]; Retention time = 4.25 mm. 1H NMR (400 MHz, DMSO-d6) delta [ppm]: 1.18 (d, J=6.26 Hz, 6 H) 2.11 - 2.25 (m, 4 H) 3.58 - 3.77 (m, 2 H).

		A solution of 2,6-dimethyl-4H-pyran-4-one (2 g, 16.1 mmol) in EtOH (20 rriL) was stirred over Pd/C (10 wt.%, 0.2 g) under hydrogen (15 psi) for 16 hrs at ambient temperature. The suspension was filtered off and the filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane (15 mL) and treated with Dess-Martin periodinane (2.3 g) at ambient temperature for 16 hrs. To the suspension was added saturated aqueous sodium thiosulfate solution (~3 mL) and the mixture was stirred for 1 hr. The mixture was diluted with saturated aqueous sodium bicarbonate solution (20 mL) and stirred for an additional 1 hr. The separated organic phase was washed with water and brine, dried over sodium sulfate, filtered through celite and concentrated under reduced pressure. The residue was purified by column chromatography [silica gel, EtO Ac/heptane = 10/90]. Fractions were combined and concentrated under reduced pressure providing (2R,6S)-2,6-dimethyldihydro-2H-pyran- 4(3H)-one (600 mg). GCMS: 128 [M]; Retention time = 4.25 mm. 1H NMR (400 MHz, DMSO-d6) delta [ppm]: 1.18 (d, J=6.26 Hz, 6 H) 2.11 - 2.25 (m, 4 H) 3.58 - 3.77 (m, 2 H).
		A solution of 2,6-dimethyl-4H-pyran-4-one (2 g, 16.1 mmol) in EtOH (20 mL) was stirred over Pd/C (10 wt.%, 0.2 g) under hydrogen (15 psi) for 16 hrs at ambient temperature. The suspension was filtered off and the filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane (15 mL) and treated with Dess-Martin periodinane (2.3 g) at ambient temperature for 16 hrs. To the suspension was added saturated aqueous sodium thiosulfate solution (~3 mL) and the mixture was stirred for 1 hr. The mixture was diluted with saturated aqueous sodium bicarbonate solution (20 mL) and stirred for an additional 1 hr. The separated organic phase was washed with water and brine, dried over sodium sulfate, filtered through celite and concentrated under reduced pressure. The residue was purified by column chromatography [silica gel, EtOAc/heptane = 10/90]. Fractions were combined and concentrated under reduced pressure providing (2R,6S)-2,6-dimethyldihydro-2H-pyran-4(3H)-one (600 mg). GCMS: 128 [M]; Retention time = 4.25 min. H NMR (400 MHz, DMSO-d6) delta [ppm]: 1.18 (d, J=6.26 Hz, 6 H) 2.11 - 2.25 (m, 4 H) 3.58 - 3.77 (m, 2 H).
		A solution of 2,6-dimethyl-4H-pyran-4-one (2 g, 16.1 mmol) in EtOH (20 ml_) was stirred over Pd/C (10 wt.%, 0.2 g) under hydrogen (15 psi) for 16 hrs at ambient temperature. The suspension was filtered off and the filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane (15 ml_) and treated with Dess-Martin periodinane (2.3 g) at ambient temperature for 16 hrs. To the suspension was added saturated aqueous sodium thiosulfate solution (~3 ml_) and the mixture was stirred for 1 hr. The mixture was diluted with saturated aqueous sodium bicarbonate solution (20 ml_) and stirred for an additional 1 hr. The separated organic phase was washed with water and brine, dried over sodium sulfate, filtered through celite and concentrated under reduced pressure. The residue was purified by column chromatography [silica gel, EtOAc/heptane = 10/90]. Fractions were combined and concentrated under reduced pressure providing (2R,6S)-2,6-dimethyldihydro-2H-pyran- 4(3H)-one (600 mg). GCMS: 128 [M]; Rt = 4.25 min. H NMR (400 MHz, DMSO-d6) delta [ppm]: 1.18 (d, J=6.26 Hz, 6 H) 2.1 1 - 2.25 (m, 4 H) 3.58 - 3.77 (m, 2 H).
		Step 1. Preparation of (2R,6S)-2,6-dimethyldihydro-2H-pyran-4(3H)-oneA solution of 2,6-dimethyl-4H-pyran-4-one (2g, 16.1 mmol) in 20ml ethanol was stirred over 10% Pd/C (0.2g) under hydrogen (15 psi) for 16 hours at ambient temperature. TLC showed two spots; one was desired product and second one was side product in a 1 : 1 ratio. GCMS M+ 128 for product, and M+ 130 for side product.Suspension was filtered off, and the filtrate was concentrated to remove solvent to give 2.3g crude product which contained -30% of the side product. The resulting oily residue was treated with 2.3g Dess-Martin periodinane in 15ml DCM at ambient temperature for 16 hours. GCMS showed oxidation was complete, desired product formation was confirmed by GCMS at M+ 128. ~3ml NaS2C03 was added to the suspension and the resulting mixture was stirred for 1 hour at ambient temperature, then 20ml saturated sodium bicarbonate solution was added to, and new mixture was stirred for another hour. The organic phase was separated, washed with water, brine, dried and filtered through celite. The filtrate was concentrated and resulting residue was purified by ISCO eluting with 10% ethyl acetate in heptane to yield 600 mg of the desired product. GCMS: M=128. HNMR: 1.5ppm (6H), 2.3ppm (4H), 3.75ppm (2H).
		A solution of 2,6-dimethyl-4H-pyran-4-one (2 g, 16.1 mmol) in EtOH (20 mL) was stirred over Pd/C (10 wt.%, 0.2 g) under hydrogen (15 psi) for 16 hrs at ambient temperatu The suspension was filtered off and the filtrate was concentrated under reduced pressure. The residue was dissolved in dichloromethane (15 mL) and treated with Dess-Martin periodinane (2.3 g) at ambient temperature for 16 hrs. To the suspension was added saturated aqueous sodium thiosulfate solution (~3 mL) and the mixture was stirred for 1 hr. The mixture was diluted with saturated aqueous sodium bicarbonate solution (20 mL) and stirred for an additional 1 hr. The separated organic phase was washed with water and brine, dried over sodium sulfate, filtered through celite and concentrated under reduced pressure. The residue was purified by column chromatography [silica gel, EtOAc/heptane = 10/90]. Fractions were combined and concentrated under reduced pressure providing (2R,6S)-2,6-dimethyldihydro-2H-pyran-4(3H)-one (600 mg). GCMS: 128 [M]; Rt = 4.25 min. 1 H NMR (400 MHz, DMSO-d6) delta [ppm]: 1 .18 (d, J=6.26 Hz, 6 H) 2.1 1 - 2.25 (m, 4 H) 3.58 - 3.77 (m, 2 H).
	With palladium 10% on activated carbon; In tetrahydrofuran; under 2585.81 Torr; for 2h;	2,6-Dimethyl-4H-pyran-4-one (14 g) and tetrahydrofuran (140 mL) were added to 10% Pd/C, dry (2.8 g) in a 250 mL SS pressure bottle and the mixture was stirred for 2 hours at 50 psi. The mixture was filtered through a nylon membrane and concentrated. The crude product was chromatographed on silica gel with 5-50% ethyl acetate/hexanes to afford the title compound.

Reference： [1]Journal of Organic Chemistry,2004,vol. 69,p. 1716 - 1719
[2]Patent: WO2009/55331,2009,A2 .Location in patent: Page/Page column 192-193
[3]Journal of Medicinal Chemistry,2020
[4]Recueil des Travaux Chimiques des Pays-Bas,1959,vol. 78,p. 91
[5]Recueil des Travaux Chimiques des Pays-Bas,1947,vol. 66,p. 486,488
[6]Journal of the Chemical Society. Chemical communications,1994,p. 687 - 688
[7]Patent: WO2007/25307,2007,A2 .Location in patent: Page/Page column 302
[8]Patent: WO2012/66065,2012,A1 .Location in patent: Page/Page column 86
[9]Patent: WO2012/66070,2012,A1 .Location in patent: Page/Page column 93-94
[10]Patent: WO2012/101065,2012,A2 .Location in patent: Page/Page column 89
[11]Patent: WO2012/101063,2012,A1 .Location in patent: Page/Page column 110
[12]Patent: WO2012/101066,2012,A1 .Location in patent: Page/Page column 70; 99-100
[13]Patent: WO2012/101064,2012,A1 .Location in patent: Page/Page column 150-151
[14]Patent: WO2014/110705,2014,A1
[15]Patent: WO2014/110687,2014,A1
[16]Patent: WO2014/110706,2014,A1
[17]Patent: US2014/275082,2014,A1 .Location in patent: Paragraph 0326
[18]Patent: WO2015/138220,2015,A1
[19]Journal of Medicinal Chemistry,2018,vol. 61,p. 3984 - 4003

4
[ 1004-36-0 ]
[ 626-53-9 ]

Yield	Reaction Conditions	Operation in experiment
60%		Following the proceduredescribed by Opatz:[ 4 ]Ba(OH)2·8H2O (10.0 g, 31.7 mmol, 2.0 equiv) was dissolved almost completely in boiling water (130mL) under an argon atmosphere. The resulting suspension was added directly to a 50 C warmsolution of 2,6-dimethyl-gamma-pyrone (1.97 g, 15.9 mmol, 1.0 equiv) in aqueous NaOH solution (8 wt %, 4mL). A yellow precipitate formed immediately. The solution was cooled slowly to 0 C, the crystalswere filtered off, washed with aqueous NaOH solution (4 wt %), and then dissolved under ice coolingin aqueous HCl solution (15 wt %, 20 mL). The resulting solution was stirred for 1 h, and extractedwith Et2O. The combined organic layers were dried over anhydrous MgSO4, filtered and concentratedunder reduced pressure. The product was recrystallized from petroleum ether to afford 1b (1.35 g,60%) as a white solid. 1H NMR (300 MHz, CDCl3): delta 15.20 (s, 1H, C), 14.17 (s, 2H, B), 5.55 (s, 1H, C), 5.13 (s, 2H, B), 3.69 (s, 4H, A), 3.39 (s, 2H, C), 2.25 (s, 3H, C), 2.23 (s, 6H, A), 2.07 (s, 3H, C), 1.97 (s, 6H,B). These data are in good agreement with those reported in the literature.
55%		11. Heptane-2,4,6-trione; 50.0 g 2,6-Dimethyl-gamma-pyrone are dissolved in 250 mL ethanol and treated with 50 mL of a 16 M aqueous solution of sodium hydroxide. This mixture is heated for 5 hours at 6O0C and for another 1 hour at 1000C. The residue is filtered off and washed with diethylether. This residue is now dissolved in water and put in 500 mL of a 3 M aqueous solution of hydrochloric acid. The aqueous phase is <n="75"/>extracted with diethylether. The combined organic phase is dried over sodium sulfate and the solvent is evaporated in vacuo. This yields 31.6 g (55%) of the title compound. M. p. 43-45 0C.

Reference： [1]European Journal of Organic Chemistry,2013,p. 6519 - 6524
[2]Beilstein Journal of Organic Chemistry,2019,vol. 15,p. 1107 - 1115
[3]Patent: WO2007/144384,2007,A1 .Location in patent: Page/Page column 73-74
[4]Helvetica Chimica Acta,1940,vol. 23,p. 1144

5
[ 1004-36-0 ]
[ 33747-09-0 ]

Yield	Reaction Conditions	Operation in experiment
99%	With palladium 10% on activated carbon; hydrogen; In ethanol; at 35℃; under 2585.81 Torr; for 17h;	The solution of compound cap 2a (73 g, 0.59 mol) in ethanol was added Pd/C (10%, 40 g) and the reaction was stirred at 35C under an H2 (50 Psi) for 17 hours. The reaction was filtered through celite and the volatiles were removed in vacuo to provide compound cap 2b (76 g, 99% yield). 1H-NMR: (CDC13) delta: 3.75 (s, 1 H), 3.44-3.40 (m, 2 H), 1.88 (d, / = 16 Hz, 2 H), 1.19 (d, / = 8 Hz, 6 H), 1.14-1.08 (m, 2 H)
99%	With palladium 10% on activated carbon; hydrogen; In ethanol; at 35℃; under 2585.81 Torr; for 17h;	The solution of compound cap 4a (73 g, 0.59 mol) in ethanol was added Pd/C (10%, 4 g) and the reaction was allowed to stir at 35 C under H2 (50 Psi) for 17 hours. The reaction was filtered through CELITE and the volatiles were removed in vacuo to provide cap 4b (76 g, 99% yield). 1H NMR: (CDC13) delta: 3.75 (s, 1 H), 3.44-3.40 (m, 2 H), 1.88 (d, / = 16 Hz, 2 H), 1.19 (d, / = 8 Hz, 6 H), 1.14-1.08 (m, 2 H).
10%	With palladium 10% on activated carbon; hydrogen; In methanol; at 20℃; under 760.051 Torr; for 24h;	To a solution of 2,6-dimethyl-y-pyrone (1.5 g, 12.1mmol) in MeOH (15 mL) was added 10% Pd/C (150.8 mg) at rt and treated with H2 (1 atm) for 24 h. After reaction completion the mixture was filtered through a Celite pad and washed with MeOH and the filtrate was concentrated under reduced pressure to give a pale yellow oil. Purification by flash chromatography using ELSD detector (Biotage Isolera, 50 g HP-SIL, 0-100 % Et20 in hexane) gave the title compound as a pale yellow oil (151 mg, 10 %). ? NMR (400 MHz, CDCl3) delta ppm 3.74-3.81 (m, 1 H), 3.45-3.49 (m, 2 H), 1.90-1.94 (m, 2 H), 1.70 (br. s, 1 H), 1.50 (br. s, 1 H), 1.22 (d, J=6.4 Hz, 6 H)

With palladium 10% on activated carbon; hydrogen; In methanol; at 50℃; under 2585.81 Torr; for 24h;

A mixture of 2,6-dimethyl-4H-pyran-4-one (50 g, 0.4 mol) and 10% Pd/C (25 g, 24 mmol) in methanol (400 mL) was stirred under 50 psi of at 50 C for 24 h. The catalyst was removed by filtration and the filtrate solvent was removed in vacuo to give the title compound. 1 H NMR delta 3.82 - 3.89 (m, 1 H), 3.67 - 3.74 (m, 1 H), 3.36 - 3.43 (m, 2 H), 1.83 - 1.87 (dd, 2 H), 1.54-1.59 (m, 1 H), 1.29 - 1.39 (m, 1H), 1.16-1.17 (d, 6 H) ppm.

Reference： [1]Patent: WO2014/110705,2014,A1 .Location in patent: Page/Page column 62
[2]Patent: WO2014/110706,2014,A1 .Location in patent: Page/Page column 61
[3]Journal of Medicinal Chemistry,2018,vol. 61,p. 3984 - 4003
[4]Patent: WO2013/53051,2013,A1 .Location in patent: Page/Page column 104
[5]Recueil des Travaux Chimiques des Pays-Bas,1959,vol. 78,p. 91
[6]Recueil des Travaux Chimiques des Pays-Bas,1947,vol. 66,p. 486,488
[7]Bulletin de la Societe Chimique de France,1950,p. 40,42
[8]Patent: WO2015/138220,2015,A1 .Location in patent: Page/Page column 58

6
[ 1004-36-0 ]
[ 2645-07-0 ]
[ 14721-91-6 ]

Yield	Reaction Conditions	Operation in experiment
	With acetic anhydride

Reference： [1]Eiden; Engelhardt [Archiv der Pharmazie und Berichte der Deutschen Pharmazeutischen Gesellschaft, 1967, vol. 300, # 3, p. 211 - 225]

7
[ 1004-36-0 ]
[ 3160-91-6 ]
[ 55558-88-8 ]

Reference： [1]European Journal of Medicinal Chemistry,1974,vol. 9,p. 255 - 258

8
[ 1004-36-0 ]
[ 15513-48-1 ]

Reference： [1]Journal of Medicinal Chemistry,1998,vol. 41,p. 4408 - 4420

10
[ 1004-36-0 ]
[ 5217-47-0 ]
[ 100958-30-3 ]

Yield	Reaction Conditions	Operation in experiment
68%	In acetic anhydride; for 5h;Reflux; Inert atmosphere;	General procedure: 2,6-dimethyl-gamma-pyrone (12.50 g, 0.100 mol) and malononitrile (6.90 g, 0.104 mol) were dissolved in 50 mL of acetic anhydride; the solution was refluxed, under nitrogen flux, for 5 h. The system was then slowly cooled down to room temperature and the crystallization of a brown compound occurred. This compound was recovered by suction filtration and recrystallized by chloroform-hexane. Light brown needle-shape crystals were obtained. The yield was 60%.
68%	With acetic anhydride;Reflux; Inert atmosphere;	General procedure: 2,6-dimethyl-g-pyrone (12.50 g, 0.100 mol) and malononitrile(6.90 g, 0.104 mol) were dissolved in 50 mL of acetic anhydride; thesolution was refluxed, under nitrogen flowing, for 5 h. The systemwas then slowly cooled down to room temperature and the crystallizationof a brown compound occurred. The compound wasrecovered by suction filtration and recrystallized by chloroformhexane.Light brown needle-shape crystals were obtained. Theyield was 60%.

Reference： [1]Journal of Materials Chemistry C,2017,vol. 5,p. 5183 - 5192
[2]Journal of Photochemistry and Photobiology A: Chemistry,2016,vol. 321,p. 79 - 89
[3]Dyes and Pigments,2016,vol. 133,p. 395 - 405
[4]Tetrahedron,2008,vol. 64,p. 3772 - 3781

11
[ 1004-36-0 ]
[ 10025-74-8 ]
DyCl₃*3C₇H₈O₂ [ No CAS ]

Reference： [1]Journal of Inorganic and Nuclear Chemistry,1970,vol. 32,p. 2899 - 2903
[2]Gmelin Handbuch der Anorganischen Chemie,Gmelin Handbook: Sc: MVol.D3, 7.7.2, page 287 - 290

12
[ 1004-36-0 ]
cis-2,6-dimethyltetrahydro-4H-pyran-4-one [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
88%	With hydrogen;palladium 10% on activated carbon; In methanol; under 19001.3 Torr; for 24h;	10 g of 2, 6-dimethyl-gamma-pyrone are dissolved in 200 ml of methanol and then 0.8 g of palladium-on- charcoal at 10% is added. The reaction mixture is stirred for 24 hours under 25 atmospheres of hydrogen. The medium is filtered and then the solvent is evaporated off. 8.81 g of cis-2, 6-dimethyltetrahydro- pyran-4-one are recovered. Yield = 88%.
	With hydrogen;palladium on carbon; In ethanol; under 2585.81 Torr;	Synthesis of (2R)-3-(2-amino-6-o-tolylquinolin-3-yl)-N-(cis-2,6-dimethyltetrahydro- 2H-pyran-4-yl)-2-methylpropanamide; Stepl :; A solution of 2,6-dimethyl-4-pyrone (5.0 g, 40.3 mmol) in ethanol was charged with Pd/C (0.86 g, 0.40 mmol). The mixture was subjected to pressurized H2 conditions using a parr hydrogenator (50 psi) and the mixture was shaken overnight. Afterwards, the mixture was filtered through a pad of celite, and the filtrate was concentrated. The crude material was purified by column chromatography using 5% to 60% EtOAc-hexanes eluent. The desired fractions were combined and concentrated to give cis-2,6- dimethyldihydro-2//-pyran-4(3//)-one as a colorless oil.
	With 5%-palladium/activated carbon; hydrogen; In ethanol; under 2068.65 Torr; for 24h;Inert atmosphere;	Preparative Example 5.4 czs-2,6-Dimethyltetrahydro-4H-pyran-4-on 2,6-Dimethyl-4H-pyran-4-one (2.0 g, 16 mmol) was dissolved in ethanol (10 niL) and purged under nitrogen. Palladium on carbon (5%, 200 mg) was then added and the reaction mixture stirred under hydrogen gas (40 psi) for 24 hours. The reaction mixture was filtered over CELITE, rinsed with ethanol, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (5 to 30% EtOAc/hexanes) to afford cis-2,6- dimethyltetrahydro-4H-pyran-4-one as a colorless liquid. XH NMR (500 MHz, CDC13) delta 3.77- 3.70 (m, 2H), 2.38-2.32 (m, 2H), 2.25-2.20 (m, 2H), 1.32 (d, J = 6.1 Hz, 6H).

With hydrogen;palladium 10% on activated carbon; In ethanol; under 1520.1 Torr; for 2h;

[0343] Intermediate X13 was prepared from commercially available 2,6-dimethyl-g- pyrone (Aldrich Chemical Co., Milwaukee, Wisconsin, USA). A solution of the g-pyrone was dissolved in EtOH and hydrogenated (2 atm. H2) with 10% Pd/C over 2h. The catalyst was subsequently filtered off and the solution was concentrated in vacuo to yield crude X13 which was purified by "column chromatography to yield pure compound X13. 1H-NMR (CDCl3, 500 MHz): 3.72 (m, 2H), 2.35 (m, 2H), 2.21 (dd, 2H), 1.32 (d, 6H) ppm.

Reference： [1]Patent: WO2010/63773,2010,A1 .Location in patent: Page/Page column 18
[2]Patent: WO2011/63233,2011,A1 .Location in patent: Page/Page column 76
[3]Patent: WO2013/192125,2013,A1 .Location in patent: Page/Page column 133
[4]Patent: WO2008/106139,2008,A1 .Location in patent: Page/Page column 471

13
[ 1004-36-0 ]
C₇H₁₄O₂ [ No CAS ]
[ 752244-29-4 ]

Yield	Reaction Conditions	Operation in experiment
	With hydrogen;palladium 10% on activated carbon; In ethanol; at 20℃; under 775.743 Torr; for 16h;	Step 1. Preparation of (2R,6S)-2,6-dimethyldihydro-2H-pyran-4(3H)-one; A solution of 2,6-dimethyl-4H-pyran-4-one (2 g, 16.1 mmol) in 20 ml ethanol was stirred over 10% Pd/C (0.2 g) under hydrogen (15 psi) for 16 hours at ambient temperature. TLC showed two spots; one was desired product and second one was side product in a 1:1 ratio. GCMS M+ 128 for product, and M+ 130 for side product.Suspension was filtered off, and the filtrate was concentrated to remove solvent to give 2.3 g crude product which contained 30%> of the side product. The resulting oily residue was treated with 2.3 g Dess-Martin periodinane in 15 ml DCM at ambient temperature for 16 hours. GCMS showed oxidation was complete, desired product formation was confirmed by GCMS at M+ 128. 3 ml NaS2CO3 was added to the suspension and the resulting mixture was stirred for 1 hour at ambient temperature, then 20 ml saturated sodium bicarbonate solution was added to, and new mixture was stirred for another hour. The organic phase was separated, washed with water, brine, dried and filtered through celite. The filtrate was concentrated and resulting residue was purified by ISCO eluting with 10% ethyl acetate in heptane to yield 600 mg of the desired product. GCMS: M=128. HNMR: 1.5 ppm (6H), 2.3 ppm (4H), 3.75 ppm (2H).

Reference： [1]Patent: US2011/28492,2011,A1 .Location in patent: Page/Page column 22

14
[ 1004-36-0 ]
[ 105-56-6 ]
[ 58537-99-8 ]

Reference： [1]Journal of labelled compounds and radiopharmaceuticals,2010,vol. 53,p. 457 - 459

15
[ 1004-36-0 ]
[ 1095-03-0 ]
[ 1289220-07-0 ]

Reference： [1]Chemistry - A European Journal,2011,vol. 17,p. 3856 - 3867

16
[ 1004-36-0 ]
[ 752244-29-4 ]
[ 33747-09-0 ]

Yield	Reaction Conditions	Operation in experiment
	With hydrogen;palladium on carbon; In ethanol; at 20℃; under 3620.13 Torr; for 12h;	C - 179, Step a[00310] 2,6-Dimethyl-4H-pyran-4-one (10 g, 81 mmol) was dissolved in ethanol (125 niL) and Pd/C (1 g, 0.94 mmol) was added. The mixture was hydrogenated in a Pan- shaker under ¾ (0.325 g, 161 mmol) (70 psi) at room temperature for 12 hrs. The catalyst was filtered through a pad of CELITE and washed with ethanol. The filtrate was concentrated in vacuum and he residue was purified via BIOTAGE (2% to 25 % EtO Ac/Hex; 160g column). Two fractions of clear oils were isolated. The first eluting one corresponded to (2R,6S)-2,6-dimethyldihydro-2H-pyran-4(3H)-one (1.8 g) while the second one corresponded to Cap- 179, Step a (1.8 g).[00311] (2R,6S)-2,6-Dimethyldihydro-2H-pyran-4(3H)-one data: XH NMR (500 MHz, CDC13) delta ppm 3.69 (2 H, ddd, J=11.29, 5.95, 2.29 Hz), 2.24 - 2.36 (2 H, m), 2.08 - 2.23 (2 H, m), 1.18 - 1.34 (6 H, m); 13C NMR (126 MHz, CDC13) delta ppm 206.96 (1 C, br. s.), 72.69 (2 C, s), 48.70 (2 C, s), 21.72 (2 C, s).[00312] Cap-179, Step a data: ¾ NMR (500 MHz, CDC13) delta ppm 3.69 - 3.78 (1 H, m), 3.36 - 3.47 (2 H, m), 2.10 (1 H, br. s.), 1.88 (2 H, dd, J=12.05, 4.73 Hz), 1.19 (6 H, d, J=6.10 Hz), 1.10 (2 H, q, J=10.70 Hz); 13C NMR (126 MHz, CDC13) delta ppm 71.44 (2 C, s), 67.92 (1 C, s), 42.59 (2 C, s), 21.71 (2 C, s).

Reference： [1]Patent: WO2011/75439,2011,A1 .Location in patent: Page/Page column 143

17
[ 1004-36-0 ]
[ 594-45-6 ]
[ 1325228-59-8 ]

Yield	Reaction Conditions	Operation in experiment
97%	In methanol for 1h; Reflux;	1. General procedure for preparation of pyrylium sulfanates General procedure: 0.03 mole of sulfonic acid was dissolved in 50 mL methanol and equimolar amount of 4-pyrone soluble in methanol was added. The mixture was stirring and heating at boiling point of methanol using reflexive condenser for 1h. Methanol was removed under reduced pressure (60 °C, 30×102 Pa). The obtained liquid product was shaken with 20 mL diethyl ether and dried out under vacuum for 3 hours or obtained solid product was crystallized from the mixture of methanol/toluene, 1:5.

Reference： [1]Pernak, Juliusz; Swierczynska, Anna; Kot, Mariusz; Walkiewicz, Filip; MacIejewski, Hieronim [Tetrahedron Letters, 2011, vol. 52, # 33, p. 4342 - 4345]

18
[ 1004-36-0 ]
[ 53439-88-6 ]
[ 1334919-24-2 ]

Reference： [1]Russian Journal of Organic Chemistry,2011,vol. 47,p. 1190 - 1193

19
[ 1004-36-0 ]
[ 33747-09-0 ]
[ 33747-09-0 ]

Yield	Reaction Conditions	Operation in experiment
	With hydrogen;palladium 10% on activated carbon; In ethanol; at 20℃; under 3620.13 Torr; for 72h;	C -179, step a2,6-Dimethyl-4H-pyran-4-one (15 g, 121 mmol) was dissolved in ethanol (300 mL) and 10 % Pd/C (1.28 g, 1.21 mmol) was added. The mixture was hydrogenated in a Parr shaker under ¾ (70 psi) at room temperature for 72 hrs. The reaction mixture was filtered through a pad of diatomaceous earth (Celite ) and washed with ethanol. The filtrate was concentrated in vacuum and the residue was purified via flash chormatography (10% to 30 % EtO Ac/Hex). Two fractions of clear oils were isolated. The first eluting fractions were a mixture of (2R,4r,6S)-2,6- dimethyltetrahydro-2H-pyran-4-ol (Cap-1, step a) and (2R,4s,6S)-2,6- dimethyltetrahydro-2H-pyran-4-ol (1.2 g) while the latter eluting fractions corresponded to only Cap-179, step a (10.73 g). XH NMR (500 MHz, CDC13) delta ppm 3.69 - 3.78 (1 H, m), 3.36 - 3.47 (2 H, m), 2.10 (1 H, br. s.), 1.88 (2 H, dd, J=12.05, 4.73 Hz), 1.19 (6 H, d, J=6.10 Hz), 1.10 (2 H, q, J=10.70 Hz). 13C NMR (126 MHz, CDC13) delta ppm 71.44 (2 C), 67.92 (1 C), 42.59 (2 C), 21.71 (2 C).
	With hydrogen;palladium 10% on activated carbon; In ethanol; at 20℃; under 3620.13 Torr; for 72h;	2,6-Dimethyl-4H-pyran-4-one (15 g, 121 mmol) was dissolved in ethanol(300 mL) and 10 % Pd/C (1.28 g, 1.21 mmol) was added. The mixture was hydrogenated in a Parr shaker under ¾ (70 psi) at room temperature for 72 hrs. The reaction mixture was filtered through a pad of diatomaceous earth (Celite ) and washed with ethanol. The filtrate was concentrated in vacuum and the residue was purified via flash chormatography (10% to 30 % EtO Ac/Hex). Two fractions of clear oils were isolated. The first eluting fractions were a mixture of (2R,4r,6S)-2,6- dimethyltetrahydro-2H-pyran-4-ol (Cap-1, step a) and (2R,4s,6S)-2,6- dimethyltetrahydro-2H-pyran-4-ol (1.2 g) while the latter eluting fractions corresponded to only Cap-1, step a (10.73 g). 1H NMR (500 MHz, CDC13) delta ppm 3.69 - 3.78 (1 H, m), 3.36 - 3.47 (2 H, m), 2.10 (1 H, br. s.), 1.88 (2 H, dd, J=12.05, 4.73 Hz), 1.19 (6 H, d, .7=6.10 Hz), 1.10 (2 H, q, J=10.70 Hz). 13C MR (126 MHz, CDC13) delta ppm 71.44 (2 C), 67.92 (1 C), 42.59 (2 C), 21.71 (2 C).

Reference： [1]Patent: WO2012/21591,2012,A1 .Location in patent: Page/Page column 50
[2]Patent: WO2012/109080,2012,A1 .Location in patent: Page/Page column 21-22

20
[ 1004-36-0 ]
[ 53439-88-6 ]
[ 1443425-43-1 ]

Reference： [1]Russian Journal of Organic Chemistry,2013,vol. 49,p. 779 - 781
Zhurnal Organicheskoi Khimii,2013,vol. 49,p. 794 - 796,3

21
[ 1004-36-0 ]
C₇H₁₄O₂ [ No CAS ]

Yield	Reaction Conditions	Operation in experiment
99%	With palladium 10% on activated carbon; hydrogen; In ethanol; at 35℃; under 2585.81 Torr; for 17h;	The solution of compound cap 2a (73 g, 0.59 mol) in ethanol was added Pd/C (10%, 40 g) and the reaction was stirred at 35C under an H2 (50 Psi) for 17 hours. The reaction was filtered through celite and the volatiles were removed in vacuo to provide compound cap 2b (76 g, 99% yield). 1H-NMR: (CDC13) delta: 3.75 (s, 1 H), 3.44-3.40 (m, 2 H), 1.88 (d, J= 16 Hz, 2 H), 1.19 (d, J= 8 Hz, 6 H), 1.14-1.08 (m, 2 H).

Reference： [1]Patent: WO2014/110687,2014,A1 .Location in patent: Page/Page column 43

22
[ 1004-36-0 ]
[ 7091-13-6 ]
2,6-bis((E)-2-butoxystyryl)-4H-pyran-4-one [ No CAS ]