反应详情

温度

-60 °C

60 ml of a 20% solution of butyllithium in cyclohexane were added at -65° C. to a mixture of 26 g of tert.-butyl (1R, cis) 2,2-dimethyl-3-(2,2-dibromovinyl)-cyclopropane-carboxylate and 175 ml of anhydrous tetrahydrofuran and the mixture was stirred at -60° C. for one hour. A current of carbon dioxide was bubbled through the mixture for 90 minutes and the mixture was poured into an ice-water mixture containing N sodium hydroxide. The alkaline aqueous phase was acidified to a pH of 4 and was extracted with ether. The organic phase was dried and evaporated to dryness under reduced pressure. The residue was crystallized from petroleum ether (b.p.=60°-80° C. to obtain 8.3 g of tert.-butyl (1R,cis) 2,2-dimethyl-3-(3-hydroxy-3-oxo-1-propynyl)-cyclopropane-1-carboxylate melting at 144° C.

1. customA current of carbon dioxide was bubbled through the mixture for 90 minutes
2. additionthe mixture was poured into an ice-water mixture
3. additioncontaining N sodium hydroxide
4. extractionwas extracted with ether
5. customThe organic phase was dried
6. customevaporated to dryness under reduced pressure
7. customThe residue was crystallized from petroleum ether (b.p.=60°-80° C.