Stereoselective Reduction of 1-Benzyl-3,3-Dimethyl-5-Methylenepyrrolidine-2,4-Dione Using Sodium Borohydride With Selected Metal Chlorides

Abstract

1-benzyl-3,3-dimethyl-5-methylenepyrrolidine-2,4-dione is an intermediate product produced in the synthesis towards the natural bioactive compound, zopfiellamide A. This compound was synthesized via four main steps including dimethylations, addition with CuBr 2 , cyclization with benzylamine and reaction with formaldehyde. The corresponding intermediate was an α,ßunsaturated ketone having exo-alkene group, and it was subjected to reduction using sodium borohydride and selected metal chlorides. In this study, the effect and the hydride transfer mechanism of sodium borohydride-metal chlorides system in the reduction of 1-benzyl-3,3-dimethyl-5-methylenepyrrolidine-2,4-dione was investigated based on the stereochemical outcome of the product.