Copper-Catalyzed Mukaiyama-Michael Reactions

Significance

g-Butenolides are important chiral building blocks in organic synthesis and common subunits in natural and biological active compounds. A novel enantioselective synthesis of g-butenolide derivatives using the bis(oxazoline)-copper(II)-catalyzed Mukaiyama-Michael reaction of 2-(trimethylsilyloxy)furan with α′-phenylsulfonyl enones is reported. Chiral γ-butenolide derivatives are efficiently obtained in good yields with excellent selectivities.