Conformationally Controlled sp3 -Hydrocarbon-Based α-Helix Mimetics

Iterative Catalyst-Controlled Diastereoselective Matteson Homologations Enable the Selective Synthesis of Benzestrol Isomers

We report the development of an iterative Matteson homologation reaction with catalyst-controlled diastereoselectivity through the design of a new catalyst. This reaction was applied to the selective synthesis of each stereoisomer of benzestrol, a bioactive compound with estrogenic activity featuring three contiguous stereocenters. The different stereoisomers were assayed to determine their binding affinity for the estrogen receptor α (ERα), and the absolute configuration of the compound having uniquely high activity was determined. This research lays a framework for the catalytic synthesis and study of complete stereoisomeric sets of other bioactive molecules and chemical probes containing contiguous stereocenters.

Conformationally Controlled sp3 -Hydrocarbon-Based α-Helix Mimetics

With over 60 % of protein-protein interfaces featuring an α-helix, the use of α-helix mimetics as inhibitors of these interactions is a prevalent therapeutic strategy. However, methods to control the conformation of mimetics, thus enabling maximum efficacy, can be restrictive. Alternatively, conformation can be controlled through the introduction of destabilizing syn-pentane interactions. This tactic, which is often adopted by Nature, is not a common feature of lead optimization owing to the significant synthetic effort required. Through assembly-line synthesis with NMR and computational analysis, we have shown that alternating syn-anti configured contiguously substituted hydrocarbons, by avoiding syn-pentane interactions, adopt well-defined conformations that present functional groups in an arrangement that mimics the α-helix. The design of a p53 mimetic that binds to Mdm2 with moderate to good affinity, demonstrates the therapeutic promise of these scaffolds.