Horner-Wadsworth-Emmons olefination with aldehydes and ketones gives acrylic esters, cf Triethyl- phosphonoacetate. In general, the (E):(Z) ratio of the resulting alkene increases as the counter-ion becomes smaller (K, Na, Li) and as the temperature increases. See, e.g.: J. Org. Chem., 55, 3386 (1990). Reaction with ɑ-hydroxy ketones provides a simple route to butenolides: Tetrahedron Lett., 36, 2839 (1995).
