Rhodium-catalysed isomerisation of some unsaturated organic substrates

Abstract

The versatile rhodium trichloride trihydrate has been employed in catalytic amounts to promote double-bond migration. This method allows good yields in otherwise difficult, or impossible, exocyclic–endocyclic isomeris-ations. The rearrangement of ergosterol was found to be more complex. Besides known isomers a new cis-AB-ergosterol isomer has been isolated.