I. Catalytic Allylic Oxidation to Generate Vinylogous Acyl Sulfonates From Vinyl Sulfonates II. Synthesis of the Cucumin a Ring System via a 5-Endo-Trig Heck Cyclization

Abstract

The work presented in the first two chapters of this thesis culminated in a largely unprecedented allylic oxidation. Regioselective formation of vinylogous acyl sulfonates via allylic oxidation of the corresponding vinyl sulfonates was achieved with catalytic iron(III) chloride and stoichiometric tert-butyl hydroperoxide. The transformation exhibited tolerance of many different functional groups, including some other allylic and benzylic sites. Results were optimal for substrates with steric protection of the vinyl sulfonate moiety, although other classes of substrates were isolated in reduced yields. The final chapter of this thesis describes the asymmetric synthesis of the cucumin A (43) ring system 174 via the 5-endo-trig Heck cyclization of 173. Intermediate 173 was derived from enantioenriched 160, which was forged from building blocks 158 and 159 via the chiral pryrrolidinyl sulfonamide promoter 156.