Chemodivergent synthesis of cis-4-hydroxyprolines from diastereomerically enriched epoxides†
Abstract
A method for synthesis of cis-4-hydroxyproline analogs is described. A cis epoxide is converted into a cis-4-hydroxyproline, while the trans epoxide is converted into a ketone or α-aminolactone in the presence of Lewis and Brønsted acids. We propose the divergent chemoselectivity is controlled by H-bonding within the cis epoxide.