反应详情

A solution of trans-3,3-diethoxy-1,2-cyclobutanedicarboxylic acid, diethyl ester (100 g) in 1400 ml of tetrahydrofuran under argon was treated with 1400 ml of methanol and 1400 ml of 1N potassium hydroxide solution. The resulting mixture was allowed to stand for 3 days at room temperature and then was evaporated in vacuo to an aqueous solution. The pH was adjusted to 2.3 with 3N hydrochloric acid and the solution was saturated with sodium chloride. The resulting suspension was extracted with ethyl acetate (3×1000 ml). The combined extracts were washed with 250 ml of water and 250 ml of brine, dried over sodium sulfate, and evaporated to afford the product as solid, 78.8 g, m.p. 118°-120° C.

1. customwas evaporated in vacuo to an aqueous solution
2. extractionThe resulting suspension was extracted with ethyl acetate (3×1000 ml)
3. washThe combined extracts were washed with 250 ml of water and 250 ml of brine
4. dry with materialdried over sodium sulfate
5. customevaporated