Protecting-group-free synthesis of haterumadienone- and puupehenone-type marine natural products

Abstract

A divergent and expeditious access to haterumadienone- and puupehenone-type marine natural products has been achieved by using a newly developed hemiacetalization/dehydroxylation/hydroxylation/retro-hemiacetalization tandem reaction as one of the key steps. Its applicability is showcased by the first synthesis of haterumadienone, 20-hydroxyhaterumadienone, 20-epihydroxy-haterumadienone and 20-acetoxy-haterumadienone, as well as the facile synthesis of puupehenone, puupehedione and puupehenol. The synthesis is efficient, and atom- and step-economical (6 to 9 steps from commercially available starting materials), and requires no protecting groups and transition metals.