反应详情

To a solution of trans-3-acetoxycyclobutanecarboxylic acid methyl ester (trans/cis=5:1) (4.70 g, 27.3 mmol) in dry methanol (45 mL) was added sodium methoxide (25 wt % solution in MeOH, 0.62 mL, 2.7 mmol), and the solution was stirred at ambient temperature. More NaOMe solution (0.31 mL, 2.4 mmol) was added after 1 h and 2 h, and stirring was continued overnight. Most of the methanol was evaporated, water was added (≈100 mL), and the mixture was extracted with CH2Cl2 (6×60 mL). The combined organic layers were washed with NaHCO3 solution and brine, dried over MgSO4, filtered and concentrated (vacuum down to ≈40 mbar) to give the title compound as brown oil, trans/cis=5:1 based on 1H NMR. The material thus obtained was used without further purification. 1H NMR (CDCl3, 400 MHz) δ 2.17-2.27 (m, 2H), 2.54-2.64 (m, 2H), 3.00-3.09 (mc, 1H), 3.70 (s, 3H), 4.53-4.62 (mc, 1H).

1. stirringstirring
2. customMost of the methanol was evaporated
3. additionwater was added (≈100 mL)
4. extractionthe mixture was extracted with CH2Cl2 (6×60 mL)
5. washThe combined organic layers were washed with NaHCO3 solution and brine
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated (vacuum down to ≈40 mbar)