Chiral Potassium Brønsted Base-Catalyzed Stereoselective Synthesis of 1,3-Diols via a Tandem Allylic Isomerization/Asymmetric Aldol–Tishchenko Reaction

A series of chiral potassium Brønsted bases containing 3,3 ́-substituted BINOL-based chiral crown ethers are demonstrated as sustainable metal catalysts for a tandem allylic isomerization/asymmetric aldol–Tishchenko reaction. The crown ether creates an effective chiral environment around the potassium cation, yielding diverse 1,3-diols containing three contiguous stereogenic centers with excellent diastereoselectivity and high enantioselectivity. This system allows the use of allylic alcohols instead of enolizable ketones and aldehydes as nucleophiles, thus broadening the synthetic applicability of this reaction.