chapter  2
8 Pages

Synthesis of Higher-Carbon Sugars Using the Phosphonate Methodology: Part II—Synthesis of Dimethyl (methyl 2,3,4-Tri- O-benzyl-α-d-gluco-heptopyranos-6-ulos-7-yl)phosphonate and Application for Carbon Chain Elongation

General Methods ...................................................................................................... 13 Dimethyl (methyl 2,3,4-tri-O-benzyl-α-d-gluco-heptopyranos-6-ulos-7-yl) phosphonate (2) ................................................................................................... 13 Methyl 2,3,4-Tri-O-benzyl-7,8-dideoxy-7(E)-eno-9,10-O-isopropylidened-glycero-α-d-gluco-dec-1,5-pyranosid-6-ulose (4) ........................................... 14

References ................................................................................................................ 18

Higher-carbon sugars can be conveniently synthesized according to the methodology shown in Scheme 2.1. It is based on a coupling of a carbohydrate phosphonate I with a carbohydrate aldehyde II, which provides the higher carbohydrate enone III in good yield and with (almost exclusively) E-conguration across the double bond.1 The method is applicable to making higher carbohydrates of almost unrestricted chain length. We have already reported the synthesis of the C21-monosaccharide by coupling of a C12-aldehyde and the C9-phosphonate 2.2

In this chapter, we present a model synthesis of the higher carbohydrate enone composed of two units derived from d-glucose and d-glyceraldehyde. In the procedure, we will also present an efcient method of the synthesis of phosphonate 23 (derivative of d-glucose) and its application in the preparation of higher-carbon sugars.