Question

Question: What compound forms geranial (Figure 21.6) by a Cope rearrangement ?

Short answer

Answer

Step-by-step solution

Geranial

Geranial comes under the category of compounds termed terpenoids. It is an isomer of citral comprising the molecular formula and is termed as citral-A.

Cope rearrangement

There are several [3,3] sigmatropic rearrangements, and one among them is the Cope rearrangement. A molecule of 1,5-diene gets subjected to cope rearrangement to give rise to isomeric 1,5-diene.

Identifying the compound that forms geranial by Cope rearrangement

Geranial undergoes [3,3] sigmatropic rearrangement to form 3, 3-dimethyl-2-(prop-1-en-2-yl)pent-4-enal. The chemical reaction can be given as:

Compound that forms geranial by Cope rearrangement

Hence, the compound formed by the Cope rearrangement of geranial is 3, 3-dimethyl-2-(prop-1-en-2-yl)pent-4-enal.