huckel rule??HELP

[utdent20]

---

Members don't see this ad.

So i think i've posted before that i don't understand aromaticity.. i 've gottent the part that the structure must be a ring and conjugated but teh counting of electrons and charges via huckel rule still not comprehending to my mind!!.. lookign at # 44 on the destroyer.. why is choice B horrible?? or C not aromatic.. I need to understand i am taking this in a week.. HELP HELP!! PLEASE...
also
What are the rules that go for the tollens and benedicts test?? if tollens turns out positive what is it?? and so on..

 

[keliao]

my way to determine:
Aromatic (2,6,10,14,18...)
Anti (4,8,12,16,...)
NON aromatic (has sp3)

counting: one doublebond equals 2, one lone pair = 2, one oxygen in a ring count 2, or one (S) in a ring count 2, one NH count 2.
ex, heptalene (6 double bond = 12 pi electrons(counts) = antiaromatic)
pyridine (2 double bond + 1 double bonded to nitrogen = 6 pi e = aromatic)
cyclopentadienyl anion ( 2 double bond and an anion = 6 pi electrons= aro)

do NOT COUNT: proton (+), nor CH-N=CH

 

[utdent20]

so looking at problem # 44 in destroyer, woulnd't D be anti aromatic ???

 

[JBarr29]

No. Answer D is non-aromatic because the bottom most carbon is sp3. Just because something has 4 or 8 e-s don't automatically look for it to be anti-aromatic. if you see any sp3 Cs with four bonds, anti and aromatic are out the window pretty much. you agree keliao?