A flexible enantioselective total synthesis of diospongins A and B and their enantiomers using catalytic hetero-Diels-Alder/Rh-catalyzed 1,4-addition and asymmetric transfer hydrogenation reactions as key steps.

A unified enantioselective route to total synthesis of diospongins A and B and their enantiomers has been developed employing achiral starting materials. All three stereocenters were introduced by means of catalytic reactions.