Total synthesis of ceramides and β-O-glucosylceramides via intramolecular fatty acyl group migration

Abstract

Acyl migration of alkyl and aromatic acyl groups from an alcohol to another alcohol or amine is a phenomenon that occurs in nature and can be a bane to some synthetic strategies. An acyl migration-dependent method was developed for the synthesis of ceramide and glucosyl ceramide derivatives, in which the desired fatty acyl moiety acts both as protecting and migrating group. Removal of the tetrachlorophthalimido (TCP) group with ethylenediamine as a mild base at room temperature resulted in subsequent intramolecular fatty acyl group migration from –O to –N, on sphingosine or per acetylated glucosyl sphingosine to yield the desired N-acylated products. Deacetylation reaction afforded the desired β-O-glucosylceramide derivatives. Thus, choice of the appropriate blocking group turns acyl migration into a tool for synthesis, rather than an impediment.