Authentic standards for the reductive-cleavage method. The positional isomers of partially methylated and acetylated or benzoylated 1,5-anhydro-l-rhamnitol

Described herein is an efficient method for the synthesis of the eight positional isomers of methylated and acetylated or benzoylated 1,5-anhydro-l-rhamnitol. The compounds are generated simultaneously from 1,5-anhydro-l-rhamnitol by sequential partial methylation and benzoylation. The individual isomers are obtained in pure form by high-performance liquid chromatography. Debenzoylation and acetylation yielded the desired acetates. Reported herein are the 1H NMR spectra of the benzoates and the electron-ionization mass spectra of the acetates and the tri-O-methyl derivative. Also reported for the acetates and the tri-O-methyl derivative are their linear temperature programmed gas-liquid chromatography retention indices on three different capillary columns. The title compounds were obtained in pure form from 1,5-anhydro-l-rhamnitol by sequential methylation, benzoylation, and fractionation by HPLC. Debenzoylation and acetylation yielded the corresponding acetates.