a little confused (1 Viewer)

[humptydumpty5]

A little confused with how to name these structures

Also what determines that I would need to count backwards or even count the substituent included???

 

[may22]

For b, count the longest chain (7). Both the branches leading off are methyl groups, so you’ll end up with 3,5-dimethyl-heptane

For c, prioritise the triple bond that makes it an alkyne, count the longest chain from there, and add the substituent. Note that there will be a carbon at the beginning and end of the triple bond (before it connects to where you wrote 5). In this case, it will be called 3-butyl-1-octyne

For d, well, this is one I think you just have to know and be able to recognise; it’s benzene

I’ve attached screenshots where I have drawn around the longest chain for your reference. Hope this helps

 

[humptydumpty5]

For b, count the longest chain (7). Both the branches leading off are methyl groups, so you’ll end up with 3,5-dimethyl-heptane

For c, prioritise the triple bond that makes it an alkyne, count the longest chain from there, and add the substituent. Note that there will be a carbon at the beginning and end of the triple bond (before it connects to where you wrote 5). In this case, it will be called 3-butyl-1-octyne

For d, well, this is one I think you just have to know and be able to recognise; it’s benzene

I’ve attached screenshots where I have drawn around the longest chain for your reference. Hope this helps

omg thank you so much for your help. I just got to do more practice thanks again

 

[icycledough]

I'm not sure if this is right or not (someone can confirm with me), but in the HSC chemistry syllabus, they focus on what's called 'aliphatic chemistry', which is essentially compounds with an open chain structure, whereas 'aromatic chemistry' focuses on closed chain structures, like benzene. If I recall correctly, apart from like cyclohexane vs cyclohexene experiment in Module 7, they wouldn't test you on aromatic compounds.

 

[jazz519]

I'm not sure if this is right or not (someone can confirm with me), but in the HSC chemistry syllabus, they focus on what's called 'aliphatic chemistry', which is essentially compounds with an open chain structure, whereas 'aromatic chemistry' focuses on closed chain structures, like benzene. If I recall correctly, apart from like cyclohexane vs cyclohexene experiment in Module 7, they wouldn't test you on aromatic compounds.

They can test aromatic compounds to some extent. Look at the data sheet for the C13 NMR it has the aromatic ring in the 120 ppm area. All you need to know for this is the simple benzene one, they won't ask further than that though

Also that benzene one can still be named using that cyclohexene logic. It would be cyclohexa-1,3,5-triene (although not correct for its resonance forms that could be named using HSC format