Scavenger resin for primary amines, hydrazines, Meldrum's acid and organometallic reagents: J. Am. Chem. Soc., 93, 492 (1971); Tetrahedron Lett., 37, 7193 (1996). For a study of the symmetrical and unsymmetrical benzoin condensation in cross-linked polymer systems, see: Eur. Polym. J., 30, 881 (1994).