Electrogenerated cyanomethyl anion in organic synthesis: a simple diastereoselective synthesis of cis-3-alkyl-1-benzyl-4-ethoxycarbonyl-β-lactams

A ready diastereoselective synthesis of cis-3-alkyl-1-benzyl-4-ethoxycarbonyl-β-lactams has been developed by galvanostatic electrolysis of MeCN–Et4NPF6 solutions and subsequent addition of a N-(ethoxycarbonyl)methyl-N-benzyl-2-bromoalkylcarboxamide. The yields in β-lactams are very high and the cis isomers have been obtained in a large excess, the cis/trans ratios varying from 87/13 to 93/07.