The oxidative addition reactions of the racemic thiosulfinates S-(CH 2 ) 4 -S(O) (1) and S-CH 2 -(C 6 H 4 )-CH 2 -S(O) (4) with dppePt(η 2 -C 2 H 4 ) (6) led to the 1-sulfenato-4-thiolato platinum(II) complexes dppePt[S(O)-(CH 2 ) 4 -S] (8) and dppePt[S(O)-CH 2 -(C 6 H 4 )-CH 2 -S] (9); the crystal structure of complex 8 was determined. The oxidative addition of the racemic thiosulfinate S-CH 2 -CH(OAc)-CH(OAc)-CH 2 -S(O) [(R* S O ,R*,R*)-2] to (Ph 3 P) 2 Pt(η 2 -C 2 H 4 ) (5) gave two diastereoisomers of compound (Ph 3 P) 2 Pt[S(O)-CH 2 -CH(OAc)-CH(OAc)-CH 2 -S] (10) in a ratio 1:1. The thiosulfinates [(R* S O ,R*,R*)-2] and [(R* S O ,R*,S*)-3] reacted with [(R,R-diop)]Pt(η 2 -C 2 H 4 ) (7) to yield four diastereoisomers each of the complexes [(R,R-diop)]Pt[S(O)-CH 2 -CH(OAc)-CH(OAc)-CH 2 -S] (11) and 12 in a ratio 100:100:1:1 and 10:10:1:1, respectively. [(R* S O ,R*,S*)-3] was characterized structurally. Treatment of the mixture of diastereoisomers of complex 11 with two equivalents of dppe gave only one diastereoisomer of complex dppePt[S(O)-CH 2 -CH(OAc)-CH(OAc)-CH 2 -S] (13).