Reference:
[1] Russian Journal of General Chemistry, 2001, vol. 71, # 11, p. 1811 - 1814
[2] Journal of the Chemical Society, 1930, p. 2729,2732
[3] Yakugaku Zasshi, 1958, vol. 78, p. 939,940[4] Chem.Abstr., 1958, p. 20010
Reference:
[1] Chemical Biology and Drug Design, 2012, vol. 80, # 5, p. 647 - 656
15
[ 572-09-8 ]
[ 118-34-3 ]
Reference:
[1] Synthesis, 1998, # 2, p. 157 - 161
[2] Chemische Berichte, 1929, vol. 62, p. 2279
16
[ 20675-96-1 ]
[ 572-09-8 ]
[ 118-34-3 ]
Reference:
[1] Chemische Berichte, 1955, vol. 88, p. 16,20
17
[ 83-46-5 ]
[ 572-09-8 ]
[ 474-58-8 ]
Reference:
[1] Journal of the Chemical Society, 1913, vol. 103, p. 1022,1026
[2] Journal of Organic Chemistry, 1953, vol. 18, p. 1473,1476
[3] Collection of Czechoslovak Chemical Communications, 1973, vol. 38, p. 3273 - 3278
[4] Journal of Natural Products, 2001, vol. 64, # 7, p. 993 - 996
18
[ 572-09-8 ]
[ 474-58-8 ]
Reference:
[1] Journal of Pharmaceutical Sciences, 1985, vol. 74, # 12, p. 1259 - 1264
19
[ 112-17-4 ]
[ 604-69-3 ]
[ 112-29-8 ]
[ 572-09-8 ]
Yield
Reaction Conditions
Operation in experiment
57%
at 20℃; Irradiation; Green chemistry
General procedure: Bromine (1.5 mmol, 0.08 mL) was added slowly to a magnetic stirring barand perfluorohexanes (4.0 mL) in a test tube (14 mmφ x 105 mm) with a septum and then 1-O-acetylsugar 1a (1 mmol, 392 mg) in ethyl acetate (2.0 mL) wasadded slowly, forming three layers. The test tube was stirring upon irradiationwith 15 W black light (at 352 nm, TOSHIBA EFD15BLB-T) at 30 C. The light source wasplaced away from the test tube. After 23 hours, the bromine layer disappearedand the fluorous layer recovered transparency. The ethyl acetate layer wastaken up with a pipette. Then, additional ethyl acetate (2 mL x 4) was placedon the residual FC-72 layer, followed by decanting off. The combined ethylacetate layer was washed with water (15 mL), aqueous sat. NaHCO3 (20mL), brine (20 mL) and, dried over Na2SO4, andconcentrated. Purification by chromatography on silica gel with hexane/AcOEt = 2/1gave glycosyl bromide 2a (0.91 mmol,374 mg) in 91percent yield
(4aS,6aR,6bS,8aR,12aS,14aR,14bS)-11-Cyano-2,2,6a,6b,9,9,12a-heptamethyl-10,14-dioxo-1,3,4,5,6,6a,6b,7,8,8a,9,10,12a,14,14a,14b-hexadecahydro-2H-picene-4a-carboxylic acid (2S,3R,4S,5R,6R)-3,4,5-triacetoxy-6-acetoxymethyl-tetrahydro-pyran-2-yl ester[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
75%
With potassium carbonate;Aliquat 336; In dichloromethane; water;
Dinitrile 1 was synthesized from CDDO by the method as shown in Scheme 1. Oxalyl chloride gave acyl chloride 19 in quantitative yield. Amide 3 was prepared in 91% yield from 19 with ammonia gas in benzene. Dehydration of 3 with thionyl chloride gave 1 in 89% yield (Drefahl and Huneck, 1958). Ester 5 was synthesized in 83% yield from CDDO by a nucleophilic substitution method using an alkyl halide and DBU in toluene (reflux) (Ono et al., 1978) (Method A) Amides including imidazolides were synthesized in good yield by condensation reactions (Method B, scheme 1) between acyl chloride 19 and the corresponding amines and imidazoles. Tetra-O-acetyl-beta-D-glucopyranoside 2 was prepared in 75% yield from tetra-O-acetyl-alpha-D-glucopyranoside bromide (Lemieux, 1963) and CDDO using a phase-transfer catalyst (Bliard et al., 1994) (Scheme 2) (Method C). Because in the 1H-NMR spectrum (300 MHz, CDCl3) of 2 the anomeric proton was observed at delta5.70 ppm (1H, d, J=7.8 Hz) the proton was assigned the beta-configuration.
[(3R,4S,6S)-3,4,5-triacetoxy-6-[[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]methoxy]tetrahydropyran-2-yl]methyl acetate[ No CAS ]
[(2R,3aS,6R,7S)-6,7-diacetoxy-2-methyl-2-[[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]methoxy]-5,6,7,7a-tetrahydro-3aH-[1,3]dioxolo[4,5-b]pyran-5-yl]methyl acetate[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
With 2,4,6-trimethyl-pyridine; silver trifluoromethanesulfonate; In dichloromethane; toluene; at -78 - 20℃; for 13.17h;
To the solution of 819 mg [4-(4,4,5,5-tetramethyl-l,3,2-dioxaborolan-2-yl)phenyl] methanol (3.50 mmol, 1 eq.), 2015 mg l-bromo-2, 3,4, 6-tetra-0-acetyl-a/p-D- mannopyranose (4.90 mmol, 1.4 eq.), 467 mg s-collidine (3.85 mmol, 1.1 eq.) in 100 mL DCM 1708 mg silver trifluoromethanesulfonate (6.65 mmol, 1.9 eq.) in 15 mL toluene was added dropwise at -78 °C and the mixture was stirred at this temperature for 10 minutes. The mixture was let to warm slowly to r.t. (3 hours), then it was stirred for 10 hours. The mixture was filtered through a Celite pad, the filtrate was concentrated. The residue was purified by flash chromatography on silica gel using heptane and ethyl acetate as eluents to give Preparation 4o as first eluted product 1H NMR (500 MHz, DMSO-d6): 7.69 (m, 2H), 7.39 (m, 2H), 5.15-5.10 (m, 3H), 4.96 (d, 1H), 4.71 (d, 1H), 4.57 (d, 1H), 4.15 (dd, 1H), 4.04 (dd, 1H), 3.96 (m, 1H), 2.12-1.91 (s, 12H), 1.29 (s, 12H); and Preparation 4p as later eluted product. 1H NMR (500 MHz, DMSO-d6): 7.63 (m, 2H), 7.31 (m, 2H), 5.68 (d, 1H), 5.32 (dd, 1H), 5.05 (t, 1H), 4.59 (d, lh) 4.54 (dd, 1H), 4.53 (d, 1H), 4.12 (dd, 1H), 4.03 (dd, 1H), 3.94 (m, 1H), 2.01-1.97 (s, 9H), 1.70 (s, 3H), 1.29 (s, 12H)
1-O-((E)-2-methylpent-2-enoyl)-2,3,4,6-tetra-O-acetyl-β-D-glucopyranose[ No CAS ]
Yield
Reaction Conditions
Operation in experiment
96%
With tetraethylammonium bromide; potassium carbonate; In dichloromethane; at 20℃;Molecular sieve;
General procedure: A mixture of glucosyl bromide 1 (1.03 g, 2.5 mmol), acid (5.0 mmol), K2CO3 (0.69 g, 5.0 mmol),TEAB (0.05 g, 0.25 mmol) and 4 A MS (0.25 g) in 35 mL DCM was stirred 24?48 h at room temperature.Next, the insoluble substances, made up of the slightly soluble potassium carboxylate, 4 A MS andother salts, were filtered off. The filtrate was washed with water, and the separated organic layer wasthen washed with 25percent aqueous K2CO3 to removed any remaining potassium carboxylate. After dryingover MgSO4 and concentration in vacuo, the residue was purified via silica gel column chromatographyusing EtOAc/hexane or EtOAc/petroleum ether (1:10 to 1:1) as eluents to yield the desired product.
Method 4) 4-bromo-1-chloro-2-(4-ethoxybenzyl)benzene (4.9 g, 15 mmol) and 20 mL of tetrahydrofuran were added to a 50 mL three-necked flask, and the mixture was stirred and cooled to -5 to 0 C.Slowly add isopropylmagnesium chloride Grignard reagent (8 mL, 2 mol/L).The system was stirred at 0 C for 2 h.In another 100mL three-neck bottle,Add (2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-bromotetrahydro-2H-pyran-3,4,5-triacetyl ester (IIa, 4.1 g, 10 mmol) , tetramethylethylenediamine (10wt%),Cobalt dichloride (10 wt%) and 20 mL of 2-methyltetrahydrofuran,The system was cooled to 0 C.Slowly add the Grignard reagent in the previous 50mL bottle and add it in about 30min.After the completion of the system, the system was warmed to 25 to 30 C, and the mixture was stirred for 2 hours. The system was quenched with 1N aqueous hydrochloric acid and the organic phase was extracted with ethyl acetate.concentrate,Column chromatography (PE/EA=3/1),The target product (4.5 g, yield 84%) was obtained.
Under argon protection conditions,300 mL of dried tetrahydrofuran (THF) was added to a 1 L three-necked flask,5-bromo-2-chloro-4-ethyldiphenylmethane (65.5 g, 200 mmol)The temperature of the reaction system was controlled at -78 C with an acetone /(N-BuLi) 80 mL (2.5 mol / L, 200 mmol, 1 eq) was slowly added dropwise. The temperature of the reaction system was controlled at -78 C or lower, and the reaction was continued at the end of the dropwise addition. hour;Then, 19.1 g (100 mmol) of cuprous iodide was slowly added to the reaction system, and the temperature of the reaction system was controlledIn the -40 ~ -30 reaction 1 hour, then slowly to the reaction system drip2,3,4,6-tetra-O-acetyl-alpha-D-pyran bromoglucoseTHF solution (41.5 g, 100 mmol, THF 100 mL, 0.5 eq) was added and the reaction temperature was controlled at -40 to -30 C during the addition and maintained at that temperature for 1 hour,After the addition was complete, the temperature of the reaction system was gradually returned to room temperature for 3 hours.After the reaction was quenched under ice cooling conditions with a saturated NaHCO3 solution to quench the reaction, extracted with ethyl acetate, and the combined organic phases, the organic phase with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give a brown crude product was 59.8 g, 300 mL of anhydrous ethanol to give 53.1 g of a white solid (Compound 1:2-chloro-5- (2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl-1-yl)4'-ethoxydiphenylmethane),HPLC detection purity of 98.5% or more, the yield of 93%.