1
IUPAC name of the following is CH2=CH-CH2-CH2-C CH
- 1-hexyne-5-ene
- 1,5-hexenyne
- 1-hexene-5-yne
- 1,5-hexynene
Answer
(3) 1-hexene-5-yne
Solution
The parent chain has 6 carbon atoms with one C=C and one C C ⇒ hexenyne.
Numbering from either end gives the multiple bonds the locants 1, 5.
∵ As per NCERT (IUPAC rules), when there is a tie, the double bond gets the lower number.
⇒ Numbering starts from the CH2= end: 1CH2= 2CH- 3CH2- 4CH2- 5C 6CH
∴ Name: hex-1-en-5-yne (written in the older style as 1-hexene-5-yne).
Answer: (3)
AIPMT 2002