Amino-acids and peptides. Part XIII. Syntheses of two fourteen-membered ring cyclotetrapeptides
Abstract
The fourteen-membered ring cyclotetrapeptides cyclo-(β-alanylglycyl-β-D-aspartylglycyl) methyl ester and cyclo-[β-alanylglycyl-L-(α-amino)-β-alanylglycyl] have been synthesised through the cyclisation of the corresponding linear tetrapeptides with o-phenylene chlorophosphite.