Question

I need to draw the structure of 4-Hexenal. I understand that "hex" means it is a 6 carbon chain and the 4 tells me the aldehyde group ("al")is off the 4th carbon. My problem is how to draw the parent chain. I tried it with 6 carbons in a straight line then attached a carbon double bonded to an oxygen to the 4th carbon in the chain and bonded a hydrogen to that carbon but that wasn't correct. Can you help me set up the structure of the parent chain?

Answer 1

No. 4 means there is a double bond (alkene bond) between the C4-C5. The al group (CH=O ) is the last thing in the change. The carbon in the (CH=O) is the sixth carbon in the chain.