Preparation of 4‐Pentenoic Acid Ester of Neu5Ac and 4‐Pentenyl Glycoside of Neu5Ac and Their Application to Glycosylation.

Abstract

Glycosylation. -Two novel sialosyl donors, 4-pentenoic acid ester and pentenyl glycoside (III) of N-acetylneuraminic acid are prepared from the corresponding per-O-acetylated 2-hydroxy and 2-chloro derivative (I) of Neu5Ac, resp. Glycosylation reactions of the donors are studied using alcohols as biologically relevant acceptors. Compound (III) is a more efficient sialyl donor than its pentenoic acid ester analogue. Thus, the reaction of (III) with (IV), promoted by NIS and trifluoromethanesulfonic acid, yields the glycoside (V) stereoselectively, while the glycosylation of (III) with (VI) affords the known galactoside (VII). -(IKEDA*, K.; FUKUYO, J.; SATO, K.; SATO, M.; Chem.

Strange dibaryon and $$ \bar K $$ NN-πΣN coupled channel equation

“…It is however noticed that the KN interaction is not well determined experimentally and further investigation to find a possible the range of the resonance energy is necessary. The full content of our work will be reported elsewhere [31].…”