Synthesis of enantioenriched allenes from 1,1-cyclopropanediesters.

Highly substituted allenes were obtained by the S(N)2' addition of organocuprate reagents on 2-propargyl-1,1-cyclopropanediesters. This new methodology permits the synthesis of highly enantioenriched allenes as the reaction proceeds with retention of the enantiomeric purity of the starting cyclopropane. The use of higher order cuprates was instrumental in obtaining the reported results.