4-Toluenesulfonyl chloride → 20-Methyl-1alpha,3beta-bis(methoxycarbonyloxy)-21-p-toluenesulfonyloxypregna-5,7-diene

Participants

Reaction Steps

In 1 ml of pyridine was dissolved 81 mg of 20-methyl-1α,3β-bis(methoxycarbonyloxy)pregna-5,7-dien-21 -ol and, then, under ice-cooling, 70 mg of p-toluenesulfonyl chloride was added. The mixture was stirred at that temperature for 3 hours. The reaction mixture was then poured into ice water and extracted with diethyl ether. The extract was serially washed with aqueous copper sulfate solution, water, aqueous sodium hydrogen carbonate solution and aqueous sodium chloride solution, dried over anhydrous sodium sulfate and concentrated. The residue was purified by silica gel column chromatography to give 79 mg of 20-methyl-1α,3β-bis(methoxycarbonyloxy)-21-p-toluenesulfonyloxypregna-5,7-diene.

Provenance & Evidence