Can someone please write the name of the alkyne molecule #4?

enter image source here
I know the names of the rest of the molecules

1 Answer
May 7, 2017

#"2-pentyne"#.........

Explanation:

Well, it's a straight 5 carbon chain, so it is a #"pent"# derivative; the triple bond STARTS at #C2# (had we started numbering from the other end we would get #"3-pentyne"# which gives an unnecessarily HIGH position number. Do you agree?

Looking at the problem again, in fact I DON'T AGREE.

The fourth compound down is #"propyne"#, a THREE carbon molecule. The fifth molecule down is #"1-butyne"#. The sixth molecule down is #"2-pentyne"#.