Hydrochloric Acid → (11R,12S,13E,15S)-9-butyryloxy-11,15-bis(tert-butyldimethylsiloxy)-7-thiaprosta-8,13-dienamide

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Reaction Steps

A methylene chloride (3 ml) solution of (11R,12S,13E,15S)-9-butyryloxy-11,15-bis(tert-butyldimethylsiloxy)-7-thiaprosta-8,13-dienoic acid (201 mg) was cooled to -40° C., then isobutyl chloroformate (47 μl) and triethylamine (63 μl) were added to the solution which was then stirred as is at -40° C. for 30 minutes. Further 1 ml of 30% ammonium hydroxide solution was added and the mixture was stirred overnight while raising the temperature to room temperature. The reaction solution was diluted by ethyl acetate then was neutralized by dilute hydrochloric acid. The desired substance was extracted from the mixture by ethyl acetate and extract was successively washed by saturated sodium hydrogen carbonate and saturated sodium chloride solution. This solution was concentrated under reduced pressure, then was purified by silica gel column chromatography (45% ethyl acetate/hexane) to obtain (11R,12S,13E,15S)-9-butyryloxy-11,15-bis(tert-butyldimethylsiloxy)-7-thiaprosta-8,13-dienamide (169 mg, 84%).

Provenance & Evidence