[madscientist]

If you have a name for a structure like
" 3-ethyl-2-butene " what does the " 2 " reperesent?

I understand that the " 3 " reperesents the
" ethyl ( CH2-CH3)" position on the longest chain, but cant understand wat the other number is?
 
cheers,

madscientist

[arnyk]

The two tells you where the double bond is located.  In that case, it would be on the second carbon.

3-ethyl-2-butene
CH3-CH=C(C2H5)-CH3

[arnyk]

Also when naming alkenes/alkynes, the double/triple bond takes precedence over the substituent groups.  Name the hydrocarbon giving the lowest possible number to the double/triple bond first.  Which is why it is 3-ethyl-2-butene instead of 2-ethyl-3-butene.

[madscientist]

Thanks for the guidence, ide be lost without this site :stunned:

[Ester]

Thanks for the guidence, ide be lost without this site :stunned:

I completely co-sign!!!
I just joined today, and i am thinking Damn why didnt i find this place a month ago, when i was having extra problems in  my Organic & Bio Chem class