Cyclic dipeptides. A stereocontrolled synthesis of (2S,3R,6R)- and (2R,3R,6R)-6-tert-butoxycarbonylamino-3-methoxycarbonyl-2-methyl-5-oxo perhydro-1,4-thiazepine

Article abstract of DOI:10.1016/0957-4166(94)80115-0

A stereoselective synthesis of the title compounds, starting from commercially available amino acids, is described. The absolute stereochemistry of 3a and 3b has been deduced on the basis of ¹H NMR and chemical degradation studies. The formation of only these two isomers has been rationalized in terms of molecular mechanics calculations.