JEE MainChemistryGeneral Organic Chemistry
An alkane is represented by a Newman projection looking down a carbon-carbon bond. The front carbon is bonded to two methyl groups and one ethyl group. The back carbon is bonded to one hydrogen atom, one ethyl group, and one n-propyl group. The correct IUPAC name of this alkane is :
Options
- A4-Ethyl-5,5-dimethylheptane
- B3,3-Dimethyl-4-propylhexane
- C3,3-Dimethyl-4-ethylheptane
- D4-Ethyl-3,3-dimethylheptane
Correct answer
D. 4-Ethyl-3,3-dimethylheptane
Step-by-step solution
First, translate the Newman projection into a connectivity diagram. The front carbon ( C_F ) is bonded to two - CH ₃ groups and one - CH ₂ CH ₃ group. The back carbon ( C_B ) is bonded to one - H atom, one - CH ₂ CH ₃ group, and one - CH ₂ CH ₂ CH ₃ group. To find the longest continuous carbon chain, we must trace the longest path through the C_F-C_B bond. The longest branch attached to C_F is the ethyl group (2 carbons). The longest branch attached to C_B is the n-propyl group (3 carbons). The longest chain consis