Synthèse, à partir du D-galactose, d'un dérivé protégé de la célestosamine (6-amino -6,8-didésoxy-7-0-méthyl- D- érythro- D- galact o-octose), sucre de certains antibiotiques du groupe de la lincomycine

Abstract

Treatment of 1,2:3,4-di- O-isopropylidene-α- D-galactopyranuronyl chloride with diazoethane gave a diazoketone that was converted with methanol in the presence of boron trifluoride into a mixture of keto-ethers. One of these keto-ethers was transformed by reduction of its oxime and N-acetylation into a blocked derivative of celestosamine, which was found to be identical with 5 prepared from a natural source, i.e. lincomycine. The properties of the other two keto-ethers are in agreement with a ( D or L)- glycero- L- altro configuration ( 14) for one of them, and with the presence of a 3-oxetanone ring in the structure ( 18) of the other one.