Pyridine → 7alpha-Acetoxy-20-(5,5-dimethyl-1,3-dioxan-2-yl)-1alpha,2alpha-epoxypregn-5-en-3beta-yl acetate

HRID 1196319Notes

Reaction equation

HRID 1196319 reaction equation
[C:1]([O:4][C@H:5]1[C@@H:31]2[O:32][C@@H:30]2[C@@:29]2([CH3:33])[C:7](=[CH:8][C@@H:9]([OH:35])[C@@H:10]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:34])[C@H:11]3[CH2:12][CH2:13][C@@H:14]2[CH:15]([CH:17]2[O:22][CH2:21][C:20]([CH3:24])([CH3:23])[CH2:19][O:18]2)[CH3:16])[CH2:6]1)(=[O:3])[CH3:2].N1C=CC=CC=1.[C:42](OC(=O)C)(=[O:44])[CH3:43].C(OCC)(=O)C.CCCCCC>CN(C)C1C=CN=CC=1.C(Cl)Cl>[C:1]([O:4][C@H:5]1[C@@H:31]2[O:32][C@@H:30]2[C@@:29]2([CH3:33])[C:7](=[CH:8][C@@H:9]([O:35][C:42](=[O:44])[CH3:43])[C@@H:10]3[C@@H:28]2[CH2:27][CH2:26][C@@:25]2([CH3:34])[C@H:11]3[CH2:12][CH2:13][C@@H:14]2[CH:15]([CH:17]2[O:18][CH2:19][C:20]([CH3:23])([CH3:24])[CH2:21][O:22]2)[CH3:16])[CH2:6]1)(=[O:3])[CH3:2]

Participants

7

Reactant 4

HCID 1049PyridineHCID 7918Acetic AnhydrideHCID 21226206Ethyl acetate hexaneHCID 8674580220-(5,5-Dimethyl-1,3-dioxan-2-yl)-1alpha, 2alpha-epoxy-7alpha-hydroxypregna-5-en-3beta-yl acetate

Product 1

HCID 867458037alpha-Acetoxy-20-(5,5-dimethyl-1,3-dioxan-2-yl)-1alpha,2alpha-epoxypregn-5-en-3beta-yl acetateYield 85%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 6344DichloromethaneSolvent2×

Procedure

To a mixture of 49.0 mg (0.1 mmole) of 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxy-7α-hydroxypregn-5-en-3β-yl acetate, 0.24 m; (3 mmoles) of pyridine, 0.5 mg (0.004 mmole) of 4-(dimethylamino)pyridine and 10 ml of dry methylene chloride was added 0.12 ml (1.3 mmoles) of acetic anhydride dropwise at a temperature of 0° C. and the solution was stirred at room temperature for 10 hours. The reaction mixture was diluted with 20 ml of methylene chloride and washed with cold 1N-hydrochloric acid. The aqueous layer (washings) was extracted with methylene chloride and the extract was combined with the organic layer. The resulting mixture was washed successively with water, aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution and dried over magnesium sulfate. The solvent was distilled off under reduced pressure and the residue was purified by silica gel chromatography (eluent: ethyl acetate-hexane=1:10, v/v) to recover 45 mg of 7α-acetoxy- 20-(5,5-dimethyl-1,3-dioxan-2-yl)-1α,2α-epoxypregn-5-en-3β-yl acetate (yield: 85%).

Workup

  1. washwashed with cold 1N-hydrochloric acid
  2. extractionThe aqueous layer (washings) was extracted with methylene chloride
  3. washThe resulting mixture was washed successively with water, aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution
  4. dry with materialdried over magnesium sulfate
  5. distillationThe solvent was distilled off under reduced pressure
  6. customthe residue was purified by silica gel chromatography (eluent

Sources & evidence

ORD record
ord-03849a94b8a0440ab70dae65b693da7b
Source dataset
uspto-grants-1992_05
Patent number
US05112998

Reaction notes

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