What is the IUPAC name ?

1. As the parent name, I would choose the longest main chain.

Octene is the parent compound; count the eight carbons in a row starting from the left.

As a result of this departure from an alkane naming, the double bond begins at position (2) and, as is appropriate, assigns a lower position number to the alkene, so that, for example, "2-octene" is mentioned instead of "6-octene" because it starts from the opposite end.

After that, we have ethyl substituents on carbons 3 and 4, and methyl substituents on carbons 5 and 6, going from left to right. Therefore, the final name, without a ton of parentheses, could be:

2,6-dimethyl-2-octene (3,4-diethyl)

or

5,6-dimethyloct-2-ene (3,4-diethyl)

2. This is similar in that pentene is the parent compound because it has the longest chain—five.

Thus, the name might be:

3,3-diethylpentene

or

3,3-diethylpent-1-ene; somewhat repetitive

Since the first one is not redundant, uses the longest chain for the parent compound, is reasonably concise, and is unique, I would choose it over the second. (By the way, t-heptylpropene is not the same as

To provide an accurate answer, I need to know the specific compound or molecule for which you require the IUPAC name. Please provide the name or formula of the compound you're referring to.