Formation and characterization of 5-C-[(R)-(1-acetoxy-ethenyl)phosphinyl]-1,2,4-tri-O-acetyl-5-deoxy-3-O-methyl-β-d-xylopyranose

Treatment of 5-deoxy-3-O-methyl-5-C-phosphinyl-d-xylopyranose with acetic anhydride in pyridine gave, along with other products, a peracetylated derivative, to which the title structure was assigned on the basis of 400-MHz, ¹H-n.m.r. and high-resolution mass spectra. The previous, 5-C-[(S)-(1-acetoxyethenyl)phosphino] structure, presented for the by-product during the preparation of tri-O-acetyl-5-deoxy-5-C-(methoxyphosphinyl)-3-O-methyl-d- xylopyranoses, is now replaced by the new formulation. Possible structures of other products of the acetylation are discussed. Analysis of the mass spectrum of a sugar analog having a 5-deoxy-5-C-(phosphinyl)-d-xylopyranose ring-system is made.