Facile synthesis of 3-amino substituted piperidines from L-glutamic acid

Multi -step route toward the synthesis of enantiomerically pure 3-( N -Boc amino) piperidine derivatives is described starting from natural alpha-amino acid i . e . L -glutamic acid. This route involves the esterification of both carboxylic acid groups in one -pot to give diester followed by NaBH 4 reduction to give diol which in turn is converted to various piperidines via the reaction of corresponding ditosylate with different amines. The overall yields of substituted piperidine have been found to be 44% to 55% starting from L -glutamic acid.