Sulfuric Acid → 2-[3(S)-azido-2(R)-hydroxy-4-phenylbutyl]-N-tert.butyl-decahydro-(4aS,8aS)-isoquinoline-3(S)-carboxamide

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Reaction Steps

A solution of 237 mg (1 mmol) of N-tert.butyl -decahydro-(4aS,8aS)-isoquinoline-3(S)-carboxamide and 300 mg (1.1 mmol) of 4(S)-[1(S)-azido-2-phenylethyl]-1,3,2-dioxathiolane 2,2-dioxide in 10 ml of tetrahydrofuran was stirred at room temperature under an argon atmosphere for 2 days, during which time some white solid deposits formed. The mixture was evaporated to give a white powder which was taken up in a 10% solution of sulphuric acid in 70% aqueous methanol and heated under reflux for 30 minutes. After cooling to room temperature the solution was adjusted to pH 10 with 10% aqueous sodium hydroxide solution and extracted three times with ethyl acetate. The ethyl acetate extracts were combined, washed with sodium chloride solution, dried over anhydrous magnesium sulphate and evaporated. Purification of the crude product by flash chromatography on silica gel using n-hexane/ethyl acetate (4:1) for the elution gave 57 mg of 2-[3(S)-azido-2(R)-hydroxy-4-phenylbutyl]-N-tert.butyl -decahydro-(4aS,8aS)-isoquinoline-3(S)-carboxamide; MS: me 428 [M+H]+.

Provenance & Evidence