Thermal and Lewis acid catalysed cycloadditions of dienes 1 to dienophiles proceed with complete regio-and stereo-selectivity and provide a route to the cyclic enones.
Readily available thiophosphates containing an alpha,beta-unsaturated moiety have been efficiently converted into the novel (Z)-1,2-diheterosubstituted-1,3-dienes by treatment with sodium hydride followed by the corresponding electrophile