甲基 3-氧代螺[5.5]十一烷-4-羧酸乙酯

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of 3-oxo-spiro[5.5]undecane-2-carboxylic acid methyl ester (29.6 g) obtained in Step 3 in a mixed solvent of methanol (200 mL)-tetrahydrofuran (50 mL), sodium borohydride (4.67 g) was added in three portions under ice-cooling, followed by stirring the reaction mixture under ice-cooling for 1 hour. Then, after addition of 1N aqueous hydrochloric acid solution to the reaction mixture, the resulting insolubles were filtered off. Methanol in the filtrate was evaporated off in vacuo, followed by extraction with ethyl acetate. 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)=1:10 to 1:3) to give trans-3-hydroxy-spiro[5.5]undecane-2-carboxylic acid methyl ester (4.15 g) and cis-3-hydroxy-spiro[5.5]undecane-2-carboxylic acid methyl ester (4.9 g). cooling cooling for 1 hour the resulting insolubles were filtered off Methanol in the filtrate was evaporated off in vacuo followed by extraction with ethyl acetate The organic layer was washed with saturated brine dried concentrated The residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:10 to 1:3)

反应条件: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To a solution of dimethyl carbonate (17.9 g) in tetrahydrofuran (130 mL) were added 60% sodium hydride (9.9 g) and potassium tert-butoxide (0.14 g). To the mixture was added a solution of spiro[5.5]undecan-3-one (20.6 g) obtained in the same manner as in Step 2 in tetrahydrofuran (120 mL) at 85° C. over 2 hours, followed by stirring the reaction mixture at 85° C. for 1.5 hours. After cooling down to room temperature and adding 15% aqueous acetic acid solution (94.2 mL), the reaction mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried and concentrated to give 3-oxo-spiro[5.5]undecane-2-carboxylic acid methyl ester (29.6 g). After cooling down to room temperature the reaction mixture was extracted with ethyl acetate The organic layer was washed with saturated brine dried concentrated