2-Ethenyl-4H-1,3,2-benzodioxaphosphorin 2-oxide 2-Vinyl-4H-1,3,2-benzodioxaphosphorin 2-oxide 4H-1,3,2-Benzodioxaphosphorin, 2-ethenyl-, 2-oxide DF4372000 Phosphonic acid, vinyl-, cyclic ester with o-hydroxybenzyl alcohol