Organocatalytic dynamic kinetic resolution via conjugate addition: synthesis of chiral trans-2,5-dialkylcyclohexanones

Abstract

A novel strategy of initiating an organocatalysed dynamic kinetic resolution (dr up to 99 : 1 and er up to 94 : 6) for the synthesis of chiral trans-2,5-dialkylcyclohexanones by an asymmetric conjugate addition of dimethyl malonate on to 6-substituted cyclohexenones is reported.

Unified Enantioselective, Convergent Synthetic Approach toward the Furanobutenolide-Derived Polycyclic Norcembranoid Diterpenes: Synthesis of a Series of Ineleganoloids by Oxidation-State Manipulation of the Carbocyclic Core

“…Surprisingly, when ketone 43 was subjected to silyl enol ether formation conditions, although the starting material was fully consumed, no trace of either desired enol ether 44 or its hydrated analog were detected in the product mixture. 22 Unfortunately, alternative advancement of ketone 40 or its diol precursor (39) by selective conjugate reduction of the unsaturated lactone could not be accomplished. Although the α,β-unsaturated lactone moiety within these compounds had enabled the installation of the C(6) ketone (i.e., 39), the inability to advance further toward ent-ineleganolide (ent-1) forced another reevaluation of the synthetic strategy.…”