Macrocycles All Aflutter: Substitution at an Allylic Center Reveals the Conformational Dynamics of [13]‐Macrodilactones

Exploring the physicochemical and antiproliferative properties of biaryl-linked [13]-macrodilactones

A macrocyclic motif fosters productive protein-small molecule interactions. There are numerous examples of both natural product and designed, synthetic macrocycles that modulate the immune system, slow microbial infection, or kill eukaryotic cells. Reported here are the synthesis, physicochemical characterization, and antiproliferative activity of a group of [13]-macrodilactones decorated with a pendant biaryl moiety. Biaryl analogs were prepared by Suzuki reactions conducted on a common intermediate that contained a bromophenyl unit alpha to one of the carbonyls of the [13]-macrodilactone. Principal component analysis placed the new compounds in physicochemical context relative to a variety of pharmaceuticals and natural products. Modest inhibition of proliferation was observed in ASZ cells, a murine basal cell carcinoma line. This work underscores the value of an approach toward the identification of bioactive compounds that places the evaluation of physicochemical parameters early in the search process.

Structures of three disubstituted [13]-macrodilactones reveal effects of substitution on macrocycle conformation

The synthesis and crystal structures of three new disubstituted [13]-macrodilactones, trans-4,8-dimethyl-1,10-dioxa­cyclo­tridec-5-ene-2,9-dione, cis-4-(4-bromo­phen­yl)-13-methyl-1,10-dioxa­cyclo­tridec-5-ene-2,9-dione, and trans-11-methyl-4-phenyl-1,10-dioxa­cyclo­tridec-5-ene-2,9-dione are reported and their conformations are put in the context of other [13]-macrodilactone structures reported previously, showing that the number, location, and relative disposition of groups attached at the termini of planar units of the [13]-macrodilactones subtly influence their aspect ratios.

The synthesis and crystal structures of three new disubstituted [13]-macro­di­lactones, namely, trans-4,8-dimethyl-1,10-dioxa­cyclo­tridec-5-ene-2,9-dione, C₁₃H₂₀O₄, I, cis-4-(4-bromo­phen­yl)-13-methyl-1,10-dioxa­cyclo­tridec-5-ene-2,9-dione C₁₈H₂₁BrO₄, II, and trans-11-methyl-4-phenyl-1,10-dioxa­cyclo­tridec-5-ene-2,9-dione, C₁₈H₂₂O₄, III, are reported and their conformations are put in the context of other [13]-macrodilactone structures reported previously. Together, they show that the number, location, and relative disposition of groups attached at the termini of planar units of the [13]-macrodilactones subtly influence their aspect ratios.