ABSTRACT
Two basic types of cycloaliphatics containing cyclopentane rings are discussed compounds in which a single cyclopentane ring bears one or, more often, more than one alkyl substituent, and compounds containing two or more terminal cyclopentane lings. The Friedel–Crafts oligomerization of 1-alkenes in the presence of halocyclopentanes gives products of lower viscosity and more uniform molecular weight than oligomerization in the absence of the halocyclopentane. Alkylated cyclopentanes represent an independent class of potential lubricant base materials that are derived from cheap starting materials in two high-yields steps. Alkylcyclopentanes with a wide variety of tribologically useful properties can be prepared by simple chemical reaction sequences. The facile alkylation of cyclopentadienide anion by alkylhalides and alcohols followed by hydrogenation of the intermediate alkylcyclopentadiene provides the products. The properties of single-ring alkylcyclopentanes are determined by the number and nature of the substituents.
