反应详情

温度

-60 °C

A solution of 3α,7α,12α-triacetoxy-5β-cholanic acid-ethyl ester (5 mmol) in dry THF (100 ml) was cooled to -78° C. and lithium diisopropylamide (LDA, 5.98 g, 7.5 mmol) was added thereto. After 15 minutes, a solution of trans-2-(phenylsulfonyl)-3-phenyloxaziridine (Davis reagent, 2.06 g, 6.73 mmol) in THF (10 ml) was added. The mixture was stirred at -60° C. for 3 hours. Normal workup, followed by purification over silica gel gave two diastereomers of 3α,7α,12α-triacetoxy-23-hydroxy-5β-cholanic acid-ethyl ester. The absolute stereochemistry of the diastereomers was not determined.

1. customNormal workup, followed by purification over silica gel