General synthesis of cyclopropenones and their acetals
作者:Masahiko Isaka、Satoshi Ejiri、Eiichi Nakamura
DOI:10.1016/s0040-4020(01)88873-6
日期:——
Metalated cyclopropenone acetals 5 react with a variety of electrophiles, including alkyl halides, carbonylcompounds, vinyl iodides, vinyl triflates, and aryl iodides, to give substituted cyclopropenone acetals in high yield. Hydrolysis of the acetal under acidic conditions gives the corresponding cyclopropenone. The reaction sequence has realized an efficient synthesis of an antibiotic penitricin
A variety of substituted cyclopropenone ketals have been prepared by electrophilic trapping (protonolysis and alkylation) of sodium salts of cyclopropenone ketals that have been generated directly from the ketals of 1,3-dichloroacetone derivatives through cyclization with NaNH2 in a liq. NH3/ether mixture.