反应详情

A solution of 13.8 g of 7-oxabicyclo[4.3.0]non-2-en-8-one, prepared by following the procedures of E. J. Corey and T. Ravindranathan, Tetrahedron Letters, 4753 (1971), in 100 ml of dry methylene chloride (passed through Woelm activity grade I alumina prior to use) was stirred at -78° C. under argon as 19.0 ml (107 mmol) of diisobutylaluminum hydride was added dropwise over 0.5 hour. After 3 hours at -78° C. the reaction mixture was quenched at -78° C. by the slow addition of several ml of 10% aqueous hydrochloric acid. The resultant mixture was then stirred in an ice-water bath as 100 ml of 10% hydrochloric acid was added dropwise. The layers which formed were separated and the aqueous phase was extracted twice more with methylene chloride. The combined methylene chloride extracts were washed with brine and then with saturated aqueous sodium bicarbonate. The washed extract was dried (Na2SO4) and evaporated in vacuo to yield 12.3 g of 7-oxabicyclo[4.3.0]non-2-en-8-ol: ir (CHCl3) 14.3, 13.7, 10.87, 9.90, 9.61, 9.27, 6.90, 3.40, and 2.78 to 3.13μ (broad); nmr δ 1.0-3.0 (m, 7H), 4.0-4.8 (m, 2H) and 5.2-6.0 (m, 3H).

1. additionwas added dropwise over 0.5 hour
2. additionwas added dropwise
3. customThe layers which formed
4. customwere separated
5. extractionthe aqueous phase was extracted twice more with methylene chloride
6. washThe combined methylene chloride extracts were washed with brine
7. extractionThe washed extract
8. dry with materialwas dried (Na2SO4)
9. customevaporated in vacuo