Cytochalasin Support Studies. The C14-C19 Subunit of Cytochalasin C. Intramolecular 2 + 2 Photochemical Cycloaddition of Vinyl Sulfones

Article abstract of DOI:10.1021/jo00137a018

An intramolecular 2? + 2? photochemical cycloaddition between a six-membered ring vinyl sulfone and a five-membered ring vinylogous ester is described.The process occurs with moderate regiospecificity, the direction being controlled by a cis-acetonide moiety on the six-membered ring.Attempts to fragment the β-alkoxy sulfone adduct to trigger a DeMayo ring expansion were unsuccessful.