[KSUPaintballa]

I've tried 2-phenylbutene and 2-phyenl-2-butene.  Any clues or hints as to what I might be missing?  You don't have to give me the answer-ive found that people on this forum don't like doing that haha. 

[cpncoop]

this is kind of a trick question, because IUPAC rules would name this compound (1-methylenepropyl)benzene, or something of the like.  But it is most often called 2-phenylbutene (as you suggested) or even more commonly alpha-ethylstyrene.

[KSUPaintballa]

2-phenylbutene seems most logical to me.  I don't understand how (1-methylenepropyl)benzene works as a name.  I'm working on an online homework system that is sort of temperamental.  I tried all of of your suggestions and none of them were acceptable answers according to the system.  The question only says "Name the compound." It doesn't say name the common name or use IUPAC rules to name, so I'm not sure what it's looking for.

[bromidewind]

While it's not conventional by any means and goes against every carbon atom in my body to call it this, you could number the carbons around the ring as a chain. So it could be 3-methylene-4,6,8-nontriene. Ugh it makes me shudder to even suggest it... But all the other conventional things have been mentioned.

[Schrödinger]

I tried drawing it on Chemdraw and it says but-1-en-2-ylbenzene

[orgopete]

The ACD free demo name (http://ilab.acdlabs.com/ilab/perl/work.pl, you must select the free name from the middle toolbar option) gives (1-methylenepropyl)benzene.

This is just an opinion. I note the increasing popularity of these online resources. My own experience/frustration with them can be anticipated from the precision that a computer requires and the IUPAC rules. So, in this example, ChemDraw and ChemSketch give two different names. The difficulty of making a correct prediction and frustration that students might experience accordingly increases. I don't know the difficulty that programers experience in writing these applications for which a variety of structures might be generated and whether a variety of names might be acceptable. (I like how ChemDraw is quite flexible in interpreting chemical names, IUPAC or not, into structures, but that is not the question.)

Be that as it may, in this example we have a ChemDraw name, a ChemSketch name, and the two names suggested by the poster. The poster's names included two errors (whether submitted to the program or not ??). The first left out the locant for the double bond and the second misspelled phenyl and used an incorrect locant. To increase the difficulty of guessing a or the (?) correct name, the IUPAC rules specify placing the locant before the functional group while in the U.S., we generally place the locant before the name. Thus, I might have thought the poster had given a correct name if it were 2-phenyl-1-butene (but it would be more consistent with IUPAC if it were in that case 2-phenylbut-1-ene).

You should begin to see that trying to match a computer answer can be difficult.

From my experience, there really are a wide variety of names that one may encounter. When I began teaching, I wondered why IUPAC nomenclature was being taught as it was not generally used. However, I did resolve this issue upon realizing that the objective of learning IUPAC nomenclature was simply that it was a method of using systematic nomenclature. Once I recognized this, teaching nomenclature became easy and understandable. I used a variety of nomenclatures with a similar method of locants and substituents making up a name (including names found on the bottle). With this in mind, I generally restricted nomenclature questions to asking students to draw the structure from a name rather than the reverse. I felt this was more consistent with encountering names in German, French, pre-IUPAC, CAS in its many modifications, and names not required to adhere to any specific convention. Here is a simple example. I don't expect this common name, cholesterol, to be replaced with its IUPAC equivalent, (8S,9S,10R,13R,14S,17R)-10,13-dimethyl-17-((R)-6-methylheptan-2-yl)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol.

Just an opinion.

[Smrt guy]

2-phenyl-1-butene or 2-(1-butenyl)benzene.  The first would be more common.  You have to count the double bond position from first sp2 carbon, not the second.

[orgopete]

2-phenyl-1-butene or 2-(1-butenyl)benzene.  The first would be more common.  You have to count the double bond position from first sp2 carbon, not the second.

While 2-phenyl-1-butene can be interpreted as the posters compound, it may not necessarily be interpreted by a computer program as correct. If the name were strict IUPAC, then the name would be 2-phenylbut-1-ene.

I do not believe 2-(1-butenyl)benzene is correct. ChemDraw interprets this as 1-phenylbut-1-ene. The locant 2-should apply to a position on the benzene ring. Since it is unsubstituted, that locant is ignored.

I don't know the priority of the IUPAC names, but ChemDraw and ACD labs generate different names for this compound. I can imagine frustration in naming this compound.