[PH2](O)=O.ClC([O:7][CH2:8][CH3:9])=O.[PH2:10]([O:12][CH2:13][CH3:14])=[O:11].[CH3:15][Si](Cl)(C)C.[PH2](=O)O[Si](C)(C)CCC>C1COCC1.CC(C)=O.C(N(CC)CC)C>[OH:7][C:8]([PH:10](=[O:11])[O:12][CH2:13][CH3:14])([CH3:9])[CH3:15]Hypophosphorous acid (100%, 2.0 g, 0.03M) and ethyl chloroformate (3.3 g, 0.03M) are stirred under nitrogen at room temperature in THF (40 ml). Triethylamine (3.03 g, 0.03M) is carefully added with cooling over 1 hour. 31P nmr shows that there is 85% conversion to ethyl hypophosphite (31P nmrδ=16 ppm). Trimethylsilyl chloride (3.3 g, 0.3M) is added followed by triethylamine (3.03 g, 0.03M). The mixture is stirred for 1 hour, when conversion to ethyltrimethylsilyl phosphinate (31P nmrδ=149 ppm) is complete. Acetone (5 ml) is added and the mixture is stirred for 1 hour at 60° C. The mixture is then cooled, quenched with water and washed with methylene chloride. The aqueous phase is evaporated and the residual gum is stirred with ether. Evaporation of the ether gives ethyl (1-hydroxy-1-methylethyl)phosphinate after distillation.
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