Restricted Rotation Involving the Tetrahedral Carbon. XL. Barriers to Rotation of 9-(1-Methyl-2-propenyl)triptycenes
- 1 December 1981
- journal article
- research article
- Published by Oxford University Press (OUP) in Bulletin of the Chemical Society of Japan
- Vol. 54 (12) , 3832-3836
- https://doi.org/10.1246/bcsj.54.3832
Abstract
9-(1-Methyl-2-propenyl)triptycenes were prepared by addition of substituted benzynes to 9-(1-methyl-2-propenyl) anthracene or Dields-Alder addition of p-benzoquinone to the anthracene followed by enolization and methylation. The crystals of these compounds were pure or enriched isomers of the possible rotamers but the rotational barriers were too low to obtain every possible isomer in a pure state at room temperature. The barriers to rotation were obtained by both classical and dynamic NMR methods. These values were almost the same when the peri-substituent was either a chloro or a bromo but were definitely lower when the peri-substituent was a methyl or a methoxyl.Keywords
This publication has 10 references indexed in Scilit:
- peri‐Substituent Effects on the Rotational Barrier of 9‐(1,1‐Dimethyl‐2‐phenylethyl)triptyceneAngewandte Chemie International Edition in English, 1981
- Restricted Rotation Involving the Tetrahedral Carbon. XXXVIII. Barriers to Rotation and Population Distributions of 9-(8-Methyl-1-naphthyl)fluorene and Its 1-Methyl DerivativeBulletin of the Chemical Society of Japan, 1981
- The Conformations of 2-Phenylpropionaldehyde and Some Aliphatic Ketones. The Possible Importance of the CH/π and CH/n Interactions in Determining the Molecular Geometry of a Mobile SystemBulletin of the Chemical Society of Japan, 1980
- Restricted Rotation Involving the Tetrahedral Carbon. XXXI. Barriers to Rotation in 2,3-Dichloro-9-(1-cyano or 1-methoxycarbonyl-1-methylethy)triptycenesBulletin of the Chemical Society of Japan, 1980
- Is the Effective Size of an Alkyl Group a Gauge of Dynamic Gearing?Israel Journal of Chemistry, 1980
- Restricted Rotation Involving the Tetrahedral Carbon. XXVII. Rotamers of 9-(1-Cyano or 1-Methoxycarbonyl-1-methylethyl)triptycene Derivatives Carrying a Substituent in 1-PositionBulletin of the Chemical Society of Japan, 1979
- Restricted Rotation Involving the Tetrahedral Carbon. XVII. Isolation of Three “Diastereomeric” Rotamers of a Triptycene Type Compound and Stereoselectivity in the SynthesisBulletin of the Chemical Society of Japan, 1975
- Restricted Rotation Involving the Tetrahedral Carbon. X. Barriers to Rotation of Methyl Groups in 9-Methyltriptycene Derivatives.Bulletin of the Chemical Society of Japan, 1974
- The conformers of a nitrosamine and a carboxamide: Comparison of NMR line shape and equilibration methodsJournal of Molecular Spectroscopy, 1969
- Über Tetrachlor‐anthranilsäureEuropean Journal of Inorganic Chemistry, 1909