Ti-Catalyzed Regiodivergent Openings of Unbiased Epoxides

Significance

The first titanium-catalyzed regio­divergent ring opening of sterically and electronically unbiased epoxides, which emcompasses the popular desymmetrization of meso-epoxides, is described. For racemic epoxides, regioselectivities and ee values are modest except if a chelating group is present on one substituent. Enantio­enriched epoxides provide high selectivities and ee values due to a double asymmetric process. The hydroxyester products are useful precursors for the synthesis of γ- and δ-lactones such as (R)-4-dodecanolide (in beetle secretions) and (R)-5-dodecanolide (component of cheddar odor).