Substituted allylic sulfides 1b-f and 2d were utilized as chain-transfer agents to prepare low molecular weight polystyrene and poly(methyl methacrylate) capped with carboxy, hydroxy, trialkoxysilyl, or amino groups. End-functional polymers, prepared with ethyl α-(((carboxymethyl) thio)methyl)acrylate (2b) or α-(((carboxymethyl)thio)methyl)acrylic acid (11b), were capped with both a carboxy group and an acrylate moiety. Low molecular weight α.ω-dicarboxypolystyrene or poly(methyl methacrylate) were readily obtained by chain transfer with 11b. α-Hydroxy-ω-carboxy- and α,ω-dihydroxy-terminated polystyrene, poly(methyl methacrylate), and poly(butyl acrylate) were prepared with α-(((2-hydroxyethyl)thio)methyl)- acrylic acid (11d) and 2-hydroxyethyl α-(((2-hydroxyethy 1)thio)methyl)acrylate (l2d), respectively, while N-phthalimidoethyl α-(((2-hydroxyethyl)thio)methyl)acrylate (13d) was used to prepare polymers terminated at one end with hydroxy and at the other with a phthalamido group. 1H NMR or IR spectroscopy, titration, or derivatization was used to confirm the presence of the end groups.