In this paper, we report that the tandem asymmetric Michael addition/internal Michalis-Arbazov reaction of 1 with nucleophilic trialkylphosphites afforded optically pure 5-(S)-l-menthyloxy-4- dialkyloxy-phosphonyl-3-halo-2(5H)-furanones 4a-4d in 86%-95% yield with d.e.≥98%. The optically pure compounds 4a-4d were identified on the basis of their analytical data, such as [α]~D^2^0, UV, IR, ^1H NMR, ^1^3C NMR, MS and elemental analysis. The absolute configuration of the novel chiral phosphorous compound 4b was established X-ray crystallography.

Key words: SULFONIUM COMPOUNDS, PHENOL P, BENZOFURAN P, X-RAY DIFFRACTION ANALYSIS, CRYSTAL STRUCTURE