反应详情

To a solution of (S)-6-aza-spiro[2.5]octane-5,6-dicarboxylic acid 6-tert-butyl ester (intermediate 17, 35 g, 0.122 mol) in anhydrous THF (300 ml) was added BH3/THF (1M, 360 ml, 0.365 mol) under nitrogen at 0° C. After the addition was completed, the reaction mixture was warmed to room temperature and stirred at room temperature for overnight. The resulting mixture was evaporated to obtain a crude that was purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1). (S)-5-Hydroxymethyl-6-aza-spiro[2.5]octane-6-carboxylic acid tert-butyl ester was obtained as colourless oil (31 g), yield:86%.

1. additionAfter the addition
2. customThe resulting mixture was evaporated
3. customto obtain a crude that
4. customwas purified by silica gel chromatography (petroleum ether/ethyl acetate from 10/1 to 5/1)