Catalytic, Asymmetric Hypervinylogous Mukaiyama Aldol Reactions of Extended Furan-Based Silyl Enolates

Virtually perfect transmittal of the enolate reactivity up to five conjugated double bonds from the origin allows a series of furan-based silyloxypolyenes to add to aldehyde carbonyls at the most distant point of the molecule. Denmark’s axially chiral bisphosphoramide/SiCl4 combination catalyzes these scantly precedented, long-range Mukaiyama-type vinylogous aldol reactions efficiently, providing a palette of extended γ-alkylidene butenolide carbinols with complete ω-site selectivity and good to excellent levels of enantioselectivity.