Synthesis of 1,8-di(1-adamantyl)naphthalenes as single enantiomers stable at ambient temperatures

Single enantiomers of 1,8-di(1-adamantyl)naphthalenes were synthesized by the [4+2]cycloaddition reaction of 6-adamantyl-benzyne and 2-adamantylfuran. The enantiomers were resolved by conversion into diastereomeric ketopinic acid esters. The absolute configuration was determined by X-ray analysis. Kinetic studies by CD revealed an enantiomerization barrier of 29 kcal mol(-1) for 1,8-(1-adamantyl)naphthalenes.