Baylis-Hillman chemistry: A convenient stereoselective synthesis of (Z,Z)- and (E,E)-1,4-diallylpiperazines

Abstract

Treatment of piperazine with 3-acetoxy-2-methylenealkanenitriles provides exclusively (1,4)-bis[(2Z)-2-cyanoalk-2-en-1-yl]piperazines. A similar reaction of methyl 3-acetoxy-3-aryl-2-methylenepropanoates with piperazine produces (1,4)-bis[(2E)-3-aryl-2-methoxycarbonylprop-2-en-1-yl]piperazines as the major products.