Abstract The structure of the adduct between maleic anhydride and triphenylphosphine has been determined by direct synthesis and spectral analysis. It is analogous to a phosphine methylene derivative (WITTIG reagent) stabilized by an u-carbonyl group. With aldehydes, it gave none or very poor yields of the expected olefins; water (or alcohols) caused the anhydride ring to open, instead of forming triphenylphosphine oxide plus the ...
