反应详情

To a suspension of lithium aluminum hydride (2.38 g, 0.0627 mol) in dry THF (50 ml) was added slowly (trans)-3,3-diethoxy-1,2-cyclobutanedicarboxylic acid, diethyl ester (11.29 g, 0.0392 mol) in THF (25 ml) so that a gentle reflux was maintained. The reaction was heated at 55° for 4 hours and then diluted with ether (100 ml) and poured into saturated aqueous ammonium chloride (100 ml). The pH was lowered to 4 with 3M sulfuric acid. The suspension was extracted with ether (4×100 ml) and then chloroform (3×100 ml). The ether extracts were combined, dried over sodium sulfate, filtered and concentrated to give 5.613 g of desired product. The chloroform extracts were combined, dried over sodium sulfate, filtered and concentrated to give 112 mg of additional desired product.

1. temperaturea gentle reflux
2. temperaturewas maintained
3. temperatureThe reaction was heated at 55° for 4 hours
4. extractionThe suspension was extracted with ether (4×100 ml)
5. dry with materialdried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated