反应详情

To a suspension of MePh3PBr (37.1 g, 104 mmol) in THF (500 mL) at 0° C. was added slowly LDA (1.2 eq) over 1 h. The resulting orange solution was stirred for 30 min before ethyl 4-oxocyclohexanecarboxylate (16.1 g, 94.4 mmol) was added dropwise. The resulting suspension was warmed to rt and stirred overnight. A saturated NH4Cl (aq) was added and THF was removed. The aqueous residue was extracted with EtOAc (100 ml×3). The combined organic layers were washed with brine, dried over Na2SO4 and concentrated. The residue was purified by passing through a short silica gel plug (hexanes/EtOAc 7:1). After being concentrated, ethyl 4-methylenecyclohexanecarboxylate was obtained as a pale yellow oil (12.1 g).

1. additionwas added dropwise
2. customTHF was removed
3. extractionThe aqueous residue was extracted with EtOAc (100 ml×3)
4. washThe combined organic layers were washed with brine
5. dry with materialdried over Na2SO4
6. concentrationconcentrated
7. customThe residue was purified
8. concentrationAfter being concentrated