149849-42-3 2-Pyrrolidinone, 5,5'-((1,1,3,3-tetrabutyl-1,3-distannoxanediyl)bis(oxycarbonyl))bis-, (S-(R*,R*))- Bis(di-n-butyl(2-pyrrolidone-5-carboxylato)tin) oxide Bis(di-n-butyl-2-pyrrolidone-5-carboxylato)tin oxide