The first examples of ring-closing metathesis reactions on a phosphonate template catalyzed by the ruthenium alkylidene 3 are described. The yield, rate, and mode of cyclization in these reactions are sensitive to simple olefin substitution. The highlight of this method is the efficient syntheses of 2-alkyloxy-3, 6-dihydro-[1, 2] oxaphosphinine 2-oxide heterocycles (2).
