The cycloaddition reactions of (phenyhulfonyl)-l, 2-propadiene (1) with various l, &dipolea have been investigated. MNDO calculations suggest that the reaction of the activated allene will proceed in a highly regioselective fashion and undergo cycloaddition across the more activated a-bond. This proved to be the case in the reactions of diazomethane and diazopropane with 1. The formation of 44 (phenylsulfonyl) methyl] pyrazole (8) was ...
