反应详情

To a solution of 1-oxo-spiro[5.5]undecane-2-carboxylic acid methyl ester (13.02 g) obtained in Step 2 in methanol (300 mL), sodium borohydride (2.2 g) was added in small portions under ice-cooling, followed by stirring the reaction mixture under ice-cooling for 30 minutes. Then, after addition of saturated brine, 2N aqueous hydrochloric acid solution was further added dropwise to the reaction mixture until the evolution of gases ceased, followed by extraction with ethyl acetate twice. The organic layer was washed with saturated brine, dried and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:8 to 1:5) to give trans-1-hydroxy-spiro[5.5]undecane-2-carboxylic acid methyl ester (2.74 g).

1. temperaturecooling
2. temperaturecooling for 30 minutes
3. additionwas further added dropwise to the reaction mixture until the evolution of gases
4. extractionfollowed by extraction with ethyl acetate twice
5. washThe organic layer was washed with saturated brine
6. customdried
7. concentrationconcentrated
8. customThe residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:8 to 1:5)