Di­methyl 3,4,5,5-tetra­phenyl-1,3-thia­zolidine-2,2-di­carboxyl­ate and 3,3-di­chloro-2,2,4,4,3′-penta­methyl-r-2′,t-4′-di­phenyl­cyclo­butane-1-spiro-5′-1,3-thia­zolidine

The first of the title compounds, C₃₁H₂₇NO₄S, (V), crystallizes in the monoclinic space group P2₁/c with two independent mol­ecules in the asymmetric unit, while the second, C₂₃H₂₇Cl₂NS, (IX), crystallizes in the orthorhombic space group Pbca with one mol­ecule in the asymmetric unit. In both crystal structures, the 1,3-thia­zolidine ring adopts a half-chair conformation. The crystal structures are stabilized by weak C—H⋯O and C—H⋯Cl hydrogen bonds in (V) and (IX), respectively.