Investigation of Trimethylenemethane Cyclopentyl-Annulations as a Strategy to Obtain a Functionalized Angular
S Mason Webber1, Wade A Russu1
1Department of Pharmaceutical Sciences, Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA 95211, USA.
Abstract:
The angular triquinane carbocyclic ring system is a component of many natural products found in numerous terrestrial and marine plants. A strategy for the synthesis of functionalized angular triquinanes utilizing two trimethylenemethane (TMM)-based [3+2] cycloaddition reactions is presented. This synthetic strategy employs the intermolecular dyil-trapping reaction to give eventual access to the bicyclo[3.3.0]oct-1-en-3-one system. A subsequent [3+2] cycloaddition with a TMM equivalent provides the angular triquinane carbocyclic framework.
Related Concept Videos
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group...
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Conformations of Cycloalkanes
Chair Conformation of Cyclohexane
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
Conformations of Cyclohexane
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal...


