Part I. Stereochemistry of the Rapid Equilibration of Protonated Bicycloc[3.1.]hexenones. Part II. Control of the Stereochemistry of 2,5-cyclohexadienone Photoisomerization by Steric Factors. Part III. The Synthesis and Photorearrangement of 1,6,8,8,9,10- Hexamethyltricyclo[2.2.4.02,5]deca-3,9diene-7-one and Its Derivatives
