Development of Molecular Mechanics Torsion Parameters for α,β-Cyclopropyl α‘,β‘-Enones and Conformational Analysis of Bicyclo[m.1.0]alk-3-en-2-ones

Abstract

Conformations of cyclopropyl vinyl ketone have been studied using ab initio methods in an effort to quantify the effects of conjugative overlap between the cyclopropane ring and adjacent enone carbonyl. With respect to the cyclopropyl carbonyl torsion, cyclopropyl vinyl ketone exhibits a global energy minimum in the s-cis conformer and a local energy minimum in the s-trans conformer. The potential energy curve obtained was used to derive torsion parameters which were employed in molecular mechanics studies of the conformations of the set of bicyclo[m.1.0]alk-3-en-2-ones having larger ring sizes from 5- to 16-membered.

Diastereoselective Manipulations of Bicyclo[m.1.0]alkane Derivatives. 4. Reactions of Nucleophiles with Bicyclo[m.1.0]alk-3-en-2-ones

“…Furthermore, they present an opportunity to test further the utility of conformational analysis of medium and large carbocycles as a predictive tool for chemical reactivity. The conformational ensembles for the set of bicyclo[ m .1.0]alk-3-en-2-ones 2 possessing cis ring fusion for m = 3−14 or trans ring fusion for m = 7−14 have been studied by computational methods . In this paper, syntheses of representative enones 2 and nucleophilic 1,2- and 1,4-addition reactions of these molecules are presented and discussed.…”