Restricted Rotation Involving the Tetrahedral Carbon. XXXI. Barriers to Rotation in 2,3-Dichloro-9-(1-cyano or 1-methoxycarbonyl-1-methylethy)triptycenes

Abstract
The title compounds were prepared to see the effects of substituents in 1-position on the barriers to rotation about the C9–Csubst bond. The barrier was found to be higher for the cyano compound than those for the corresponding compounds carrying a substituent in 1-position, whereas the methoxycarbonyl compound gave almost the same barrier irrespective of the substituent.