SYNTHESIS OF NEW GLYCOPEPTIDES - APPLICAT ION TO THE PREPARATION OF NKEPHALYL)-ALPHA-D-GALACTO-OCT-6-ENOPYRANURONAMIDE

The synthesis of new glycopeptides in which the peptidic moiety is lin ked to the glucidic part through a keto alpha,beta-ethylenic handle is described. Two routes have been studied. The first strategy devised u ses Horner reagents derived from N-substituted (diethyl beta-ketophosp hono)-alpha-amino acids to effect this transformation directly from th e terminal aldehyde of a dialdose. The second is the introduction of a n alpha,beta-ethylenic carboxylic acid by Horner reaction on the same dialdose followed by classical coupling with a peptide. The second met hod, which is more general, was applied to the synthesis of kephalyl)- alpha-D-galacto-oct-6-enopyranuronamide.