Influence of the rigid spacer to macrocyclization of poly(thialactones): synthesis and computational analysis

Abstract

Influence of the rigid spacer to macrocyclization of poly(thialactones): synthesis and computational analysis Formation of macrocyclic lactones 8-19 by ring-opening condensation of corresponding stannathianes 1-4 with diacyl dichlorides 5-7 was studied experimentally and theoretically. The cyclization reactions afforded mixtures of corresponding monomers (M), dimers (D), and trimers (T). In order to rationalize the influence of type and size of the spacer on the products ratio in the M-D-T mixtures we performed a force field based molecular modeling study. Monte Carlo conformational search was conducted and lowest energy conformations in chloroform were determined. Results of the molecular modeling in combination with the assumed kinetic parameters enabled better understanding of the experimentally obtained composition of the M-D-T-mixtures. Figure 2. The most stable conformers of monomer, dimer, and trimer of 11 and 12 in chloroform as determined by MCMM conformational search. Corresponding macrocycles of 11 and 12 have the same number of atoms in the ring; however, the products yields differ significantly.