Enamine chemistry. Part XIX. Stereochemistry of the transition state of the reaction of αβ-unsaturated acid chlorides with enamines: crystal structure of 1-methyl-7-exo-t-butylbicyclo[3.3.1]nonane-2,9-dione

Abstract

Treatment of the morpholine enamine of 2-methyl-4-t-butylcyclohexanone with acryolyl chloride in boiling benzene gives 1-methyl-7-t-butylbicyclo[3.3.1]nonane-2,9-dione (VIII) as a mixture of two isomers (4 : 1). X-Ray analysis of the major isomer indicates that initial carbon–carbon bond formation occurs predominantly from the axial side of the enamine double bond. The molecular conformation is boat-chair.