A short and convenient way to produce the Taxol™ A-ring utilizing the Shapiro reaction

The Shapiro reaction was utilized in an efficient route to a Taxol™ A-ring building block. Commercially available 2-methyl-1,3-cyclohexanedione was converted in three simple steps to various arenesulfonylhydrazones and then to the target molecule with the Shapiro reaction. Remarkable differences were observed in the reactivity and stability of different hydrazones and their dianions in the Shapiro reaction. This pathway is the shortest one reported to give the target molecule in good overall yield. The use of different electrophiles in the final Shapiro reaction step allows alternative ways to prepare the target alcohol.