Prepn from maleic acid and ethanol: V. M. Mitchovitch, Bull. Soc. Chim. Fr. 4, 1667 (1937). Physical properties: G. H. Jeffrey, A. I. Vogel, J. Chem. Soc. 1948, 658. Copolymerization with styrene: F. M. Lewis et al., J. Am. Chem. Soc. 70, 1519, 1529 (1948). In Diels-Alder reactions: N. L. Bauld et al., Tetrahedron Lett. 1972, 2443. In Michael additions: G. Arsenault et al., Chem. Commun. 1983, 437. Conjugation with glutathione, q.v.: E. Boyland, L. F. Chasseaud, Biochem. J. 104, 95 (1967); eidem, ibid. 109, 651 (1968). Toxicity: H. F. Smyth et al., J. Ind. Hyg. Toxicol. 31, 60 (1949).