Reaction of cinnamic acid derivatives with sodium naphthalenide, a single-electron transfer reagent

Centre of Advanced Studies on Natural Products, Department of Chemistry University of Calcutta 92Acharya Prafulla Chandra Road, Calcutta- 700009 The reactions of the piperidides of cinnamic acid, p-methoxycinnamic acid and 3,4-dimethoxycinnamic acid with the single-electron transfer reagent sodium naphthalenide was investigated. Three products were obtained in each case-the corresponding dihydro- erivative and two diastereoisomeric piperidides of 3,4-diaryl- 1,6-hexanedioic acid resulting from reductive dimerisation. The ß,ß'- rather than \(\propto\)\(\propto\)' linkage of the 'dimers', as well as the relative configurations were settled from detailed nmr investigations and reduction studies. The dimethyl ester of 2 3-di(4'-methoxy-benzyl) succinic acid was synthesised for comparison of its nmr characteristics with those of the dimeric products. The mechanistic course of the reductive dimerisation has been rationalised.&nbsp