Substrate-controlled selective proximal and distal C-C bond cleavage via Lewis acid mediated O-acylation of 2-(arylmethylene)cyclopropylaldehyde: a stereoselective synthesis of bifunctional methylenecyclobutanes and 1,3-conjugated dienes

A new method is described for the stereoselective synthesis of bifunctional methlylenecyclobutanes by using the Zn[Cl.sub.2]-mediated reactions of (E)-2-(arylmethylene)cyclopropylaldehyde with various acyl chlorides. The reaction could be applied to obtain 1,3-conjugated dienes through distal-bond cleavage.