Effect on conformation on proton affinities of stereoisomeric ethers

✍ Scribed by C. Denekamp; A. Etinger; R. H. Fokkens; N. Khaselev; A. Mandelbaum; N. M. M. Nibbering

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 413 KB
• Volume: 30
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/jms.1190300815

✦ Synopsis

Abstract

The proton affinity (PA) of cis‐4‐tert‐butylcyclohexyl methyl either with an axial methoxy group is higher by ∼0.1 kcal mol^−1^ (1 kcal = 4.184 kJ) than the trans isomer with the equatorial ether group. The gas‐phase basicity shows a similar small difference of 0.1 kcal mol^−1^ between the two stereoisomeric ethers. A greater difference in PA has been observed between the stereoisomeric 4‐phenylcyclohexyl methyl and ethyl ethers (1.0 and 1.2 kcal mol^−1^, respectively), in favour of the cis isomers with the equatorial ether groups. The latter result is explained by the internal hydrogen bond with the π‐system of the phenyl ring.