Completely conjugated monocylic hydrocarbons are called

Options

A. annulenes
B. cumulenes
C. allenes
D. arenes

Answer

A

Explanation

Annulene is a general name for monocyclic compounds that can be represented by structures having alternate single ann double bonds. The ring size of an annulene is indicated by a number in brackets. Thus, benzene is [6] annulene and cyclooctatetraene is [8] annulene. Huckel's rule predicts that annulenes will be aromatic, provided their molecules have `(4n+2)pi` electrons and have a planar C sketeton. The name annulenes is often used for conjugated rings of 10 or more C atoms, but it is seldom used for benzene and cyclooctatetraene.