Asymmetric vinylogous Mukaiyama aldol reaction of aldehyde-derived dienolates.

Unsaturated aldehydes are exquisite building blocks for further transformations in polyketide synthesis. Besides standard transformations that take advantage of the aldehyde functionality, the conjugate addition of hydrides followed by internal protonation allows access to alpha chiral aldehydes. Even though vinylogous Mukaiyama aldol reactions have been used in natural product syntheses before, the first enantioselective Mukaiyama aldol reaction of aldehyde-derived dienolates is described.