Preparation of Sugar-Derived β-Keto Phosphonates and Their Use in the Synthesis of Higher Sugars

Article abstract of DOI:10.1021/jo00100a047

Sugar-derived β-keto phosphonates 5, 6, 7, and 8 were synthesised by the acylation of lithium dimethyl methylphosphonate with the corresponding methyl glycuronates 1, 2, and 3 and glyconate 4 in THF at -78 de C, respectively.Wadsworth-Emmons reaction of 5, 6, 7, and 8 with various sugar-derived aldehydes proceeded in good yield to produce higher sugar enones.Similarly, C-2 symmetric bis phosphonate 28 derived from L-tartrate 27 was prepared and condensed with various sugar-derived aldehydes to provide C-2 symmetric bis enones in moderate yields.Treatment of the glucose-derived β-keto phosphonate 5 with various aldehydes and excess Cs2CO3 resulted in complete cis elimination of the C-4 benzyl group along with the Wadsworth-Emmons reaction,leading to cross-conjugated dienones.