Synthesis and structure of the novel chiral 4-dialkyloxyphosphonyl-2(5H)-furanones

In this paper, we report that the tandem asymmetric Michael addition/intern al Michalis - Arbazov reaction of 1 with nucleophilic trialkylphosphites af forded optically pure 5 - ( S) - l - menthyloxy - 4 - dialkyloxy - phosphon yl - 3 - halo - 2(5H) - furanones 4a similar to 44 in 86% similar to 95% yi eld with d. e. greater than or equal to 98%. The optically pure compound 4a similar to 4d were identified on the basis of their analytical data, such as [alpha](D)(20), UV, IR, H-1 NMR, C-13 NMR, MS and elemental analysis. Th e absolute configuration of the novel chiral phosphorous compound 4b was es tablished by X - ray crystallography.