Question

draw each of the following compounds using condensed formulas:
a) 3,3,5-trimethyl-1-hexene
b) 1-bromo-3-chloro-1-heptyne
c) 3-heptyne

Not sure if I am doing this right, but for a) i put CH3C(CH3)2CH=CH3

Answer 1

a. You've drawn 1-butene with groups hanging from it. You have only two methyl groups but the name has three. And you place the two methyl groups on the 2-carbon. You start numbering from the double bond. Finally the terminal CH3 on the right has a five-valent carbon which is a no-no.
I think you want this.
CH3CH2CH2CH2CH2CH3 is hexane. Make it 1-hexene by
CH3CH2CH2CH2CH=CH2

Then hang CH3 group on 3,3, and 5
CH3CH(CH3)CH2C(CH3)2CH=CH2
6...5.....4...3.....2...1