Z-E conformational isomerism of nerol, geraniol and their acetates.

✍ Scribed by J.W. de Haan; L.J.M. van de Ven

• Publisher: Elsevier Science
• Year: 1971
• Tongue: French
• Weight: 205 KB
• Volume: 12
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)96957-6

✦ Synopsis

Introduction.

Z-E conformational isomerism of the title compounds has been a long-standing problem in terpene chemistry. In most literature the Z-("cis")-conformation is assigned to nerol, the E-("trans")-conformation to geraniol.

In 1965, Rummens 1) reversed these assignments, based mainly on IR-arguments and also on a comparison of other physical properties like boiling points, refraction indices and densities.

Relationships between NMR coupling constants (vicinal, olefinic, allylic and homoallylic) and conformation in triand tetrasubstituted ethylenes are not unambiguous 2) . It has been stated 3) that methyl substituents on olefinic double bonds have a lower d -value when cis to an alkyl substituent.