For those not well versed in organic chemistry or needs a refresher, where it is the most likely scenario you would encounter such terms, let me clarify a few points:
The -ene suffix indicates there is a double bond in the compound
The -2- indicates that the double bond is on the 2nd carbon, between carbon 2 and 3 (beta position). The placement of the n in the above post is incorrect as the location should be beside the functional group, hence the example should have been "-n-2-ene"
The -n- is a variable for the length of the carbon (e.g. prop- (3 C), but- (4 C), pent- (5 C), hex- (6 C), etc.).
Due to symmetry, you do not see the cis/trans-isomers (aka E/Z and syn/anti) unless until there is at least 4 carbons.
Hence, the easiest way to demonstrate this, is to show but-2-ene
Due to priority, the cis/trans is based on the relative position of the alkyl group rather than hydrogen in this compound (review the IUPAC naming system if you want THAT refresher)
A cis-but-2-ene has the C1 and C4 (alkyls to the left and right of the beta double bond respectively) are on the same side.
Trans-but-2-ene has C1 and C4 on opposite sides.
Hope that helps clarify matters for people. If not, look up the topic on your favorite search engine. I highly recommend checking out the Wikipedia entry first though as it may resolve it.
That is how I remember it as well.
For those not well versed in organic chemistry or needs a refresher, where it is the most likely scenario you would encounter such terms, let me clarify a few points:
The -ene suffix indicates there is a double bond in the compound
The -2- indicates that the double bond is on the 2nd carbon, between carbon 2 and 3 (beta position). The placement of the n in the above post is incorrect as the location should be beside the functional group, hence the example should have been "-n-2-ene"
The -n- is a variable for the length of the carbon (e.g. prop- (3 C), but- (4 C), pent- (5 C), hex- (6 C), etc.).
Due to symmetry, you do not see the cis/trans-isomers (aka E/Z and syn/anti) unless until there is at least 4 carbons.
Hence, the easiest way to demonstrate this, is to show but-2-ene
Due to priority, the cis/trans is based on the relative position of the alkyl group rather than hydrogen in this compound (review the IUPAC naming system if you want THAT refresher)
A cis-but-2-ene has the C1 and C4 (alkyls to the left and right of the beta double bond respectively) are on the same side.
Trans-but-2-ene has C1 and C4 on opposite sides.
Hope that helps clarify matters for people. If not, look up the topic on your favorite search engine. I highly recommend checking out the Wikipedia entry first though as it may resolve it.
https://en.m.wikipedia.org/wiki/But-2-ene
https://en.m.wikipedia.org/wiki/Cis-trans_isomerism