Abstract
The preparation and properties of N-(piperidino-oxycarbonyl)amino-acids (I) and their esters are described. The piperidino-oxycarbonyl group is stable to cold acid but is removed quantitatively by catalytic hydrogenation, by electrolytic reduction, and by zinc dust or sodium dithionite in aqueous acetic acid. Piperidino-oxycarbonylamino-acids have been coupled with amino-esters by standard methods; after saponification of the ester, the piperidino-oxycarbonyl group was removed by electrolytic reduction, giving authentic dipeptides in high yield. ε-Piperidino-oxycarbonyl-L-lysine and derivatives have been prepared, and their use in the synthesis of peptides containing lysine has been exemplified. Some N-(dimethylamino-oxycarbonyl)amino-esters are also reported.