反应详情

To a solution of the relevant 4-(1-methoxycarbonylmethyl-cyclohex-2-enyl)-butyric acid methyl ester isomer (8) or (8′) (31.0 g, 122 mmol) in dry THF (580 mL) at −78° C. was added dropwise i-Pr2NLi (2 M solution in n-heptane; 122 mL, 244 mmol). The reaction mixture was allowed to warm to room temperature and stirred for 2 hours. A saturated NH4Cl solution (700 mL) was added and the aqueous layer repeatedly extracted with Et2O. The combined organic layers were dried over anhydrous MgSO4 and the solvents removed in vacuo. The resulting residue was purified over silica (n-pentane/Et2O, 95:5) to afford 24.7 g (91% yield) of the desired product as white crystals which were characterized as follows:

1. extractionthe aqueous layer repeatedly extracted with Et2O
2. dry with materialThe combined organic layers were dried over anhydrous MgSO4
3. customthe solvents removed in vacuo
4. customThe resulting residue was purified over silica (n-pentane/Et2O, 95:5)