A very simple synthesis of GlcNAc-alpha-pyrophosphoryl-decanol: a substrate for the assay of a bacterial galactosyltransferase.

Lipid-linked sugar pyrophosphates, such as GlcNAc-pyrophosphoryl undecaprenol, are important intermediates in the biosynthesis of cell-surface bacterial polysaccharides. It was recently demonstrated that much simpler lipids could substitute for undecaprenol while retaining biological activity, thus making efficient synthetic access to this class of compounds highly desirable. In order to facilitate the synthesis of pure substrates for bacterial glycosyltransferases, we have developed a simple 'two-pot' synthesis which we demonstrate here for GlcNAc-alpha-pyrophosphoryl-decanol (4). GlcNAc pyrophosphate, produced by mild periodate oxidation/beta-elimination of commercial UDP-GlcNAc, is alkylated using 1-iododecane to yield the target compound 4 in 39% yield. Compound 4 is shown to be an efficient acceptor for a bacterial galactosyltransferase.