Pyridine → (2S,4S)-4-mercapto-2-acetylaminooxymethyl-1-p-nitrobenzyloxycarbonylpyrrolidine

Participants

Reaction Steps

To a solution of (2S,4S)-4-tritylthio-2-acetylaminooxymethyl-l-p-nitrobenzyloxycarbonylpyrrolidine (7a:452 mg) in methanol (9 ml) under ice cooling are dropwise added pyridine (149 μl) and then a solution of silver nitrate (289 mg) in a mixture of water (1.5 ml) and methanol (15 ml), and the mixture is stirred for 25 minutes. Separating silver salt is collected by filtration, washed with methanol, ether, and petroleum ether, and dried. To a suspension of this crude silver salt in a mixture of dichloromethane (3.5 ml) and methanol (3.5 ml) is introduced hydrogen sulfide gas for 5 minutes. The resulting silver sulfide is filtered off and washed with a mixture of methanol and dichloromethane. The filtrate is concentrated in vacuo. The residue is purified by silica gel chromatography to give (2S,4S)-4-mercapto-2-acetylaminooxymethyl-1-p-nitrobenzyloxycarbonylpyrrolidine (8a:198 mg) as a pale yellow foam. Yield: 73%.

Provenance & Evidence