A general method for synthesis of C-n-C (n = 1, 2...) phosphonate bonds involving a reaction of 1-diethoxy-phosphorylalkan-1-, -2-and -3-yl radicals; 1, 3, 6 with alkenes 4, a new example of functional group interconversion in I-heterosubstituted phosphonates and synthesis of useful phosphoroorganic compounds and methylenomycin B are described.