Hypophosphorous acid–iodine: a novel reducing system. Part 2: Reduction of benzhydrols to diarylmethylene derivatives

A mixture of hypophosphorous acid (H3PO2) and iodine in acetic acid reduces a variety of substituted benzhydrols to the corresponding methylene derivatives in very high yields. The active reducing agent is hydrogen iodide generated by reaction between iodine and hypophosphorous acid.