A biogenetically patterned synthetic approach to the unusual furan methylenecyclobutanol moiety in providencin

Irradiation of a solution of α,β-unsaturated aldehyde 10 in benzene leads to the methylenecyclobutanol 11 by way of a novel intramolecular C–H insertion reaction. The conversion of 10 into 11 has relevance to the possible origin of the cyclobutane ring-based furanocembrane providencin 1 found in gorgonian octocorals.