Synthesis of Neolacto Ganglioside LM1

Abstract

The synthesis of the ganglioside LM1 (1) has been performed by glycosidation of 2 with azidosphingosine 3, followed by reduction of the azido group, acylation with stearine anhydride (4), and solvolysis. 2 was obtained from sialyl xanthate 5 and tetrasaccharide 6 in the presence of phenylsulfenyl triflate. The tetrasaccharide acceptor 6 was prepared from the lactose derivatives 7 and 8.

Aliphatic aldehydes in the synthesis of carbo- and heterocycles: Part II. Synthesis of six- and seven-membered rings, bicyclic compounds, and macrocycles

“…Cycloaddition of dienes to carbonyl compounds underlies a procedure for the synthesis of 5,6-dihydropyrans. The hetero-Diels-Alder reactions were reviewed in [123,124]. As a rule, these reactions involve nucleophilic dienes and activated aldehydes.…”

Trichloroacetimidates

“…Glycosylation with a disaccharide trichloroacetimidate, which was prepared from a glucuronic acid trichloroacetimidate and a galactose acceptor, and the usual transformations including introduction of the sulfo group yielded 3-0-sulfo glucuronyl paragloboside. A more straightforward synthesis of a related structure has been reported using a Galb( 1 -4)GlcN disaccharide (lactosamine) which is contained in the neolucto structure as starting material (Scheme 22) [93].…”