Question

Write the IUPAC name of the
following compound ?*
HO
O
1-hydroxycyclohex-4-en-3-one
O
1-hydroxycyclohex-3-en-5-one
O
3-hydroxycyclohex-5-en-1-one
O
5-hydroxycyclohex-2-en-1-one​

Answer 1

Answer:

Option B is correct

1-hydroxycyclohex-3-en-5-one

hope it helps you

Answer 2

Observation of the molecule:

=> The molecule has a double bond in it and is a closed chain compound, so in its IUPAC name we use "en" .

=> It contains an "oxo" group as well as a hydroxyl group in it.

Further Explanation:

=> We know that greater preference is given to the "oxo" group.

=> So, we begin the numbering from the carbon attached to the oxo group and also, the suffix of this molecule will be "-one".

=> The prefix form of the Hydroxyl group is "hydroxy" as we will use that.

=> We number from the "Oxo" group counter-clockwise because the hydroxyl group gets greater preference than the double bond.

=> The longest carbon chain consists of six carbon atoms and the compound is cyclic so the root word is "cyclohex".

Order of preference used:

Oxo group > Hydroxyl group > Double bond

Coming Back to the IUPAC name:

=> The "Oxo" group gets the lowest numbering of one.

=> The double bond gets the numbering of five.

=> The Hydroxyl group gets the numbering of three.

=> So, the IUPAC name is : 3-Hydroxycyclohex-5-en-1-one