2012经典语录.pdf

Chapter 3Structure and Stereochemistryof Alkanes
Organic Chemistry, 5th EditionL. G. Wade, Jr.
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Chapter 3
ALKANE FORMULAS
Four carbon/or hydogen atoms bonded to
each carbon atom
All C-C single bonds
Ratio: CnH2n+2
NOTE: always an even number of
hydrogen atoms in a hydrocarbon
Alkane homologs : each member in a
alkane series different from the next
member by a CH2 group
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Chapter 3
CH3CH2CH2CH2CH2CH3
CH3CH2CH2CH2CH3
C6H14
CH2
C5H12
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Chapter 3
Lower Membered Alkanestrivial (common) names
METHANE
ETHANE
PROPANE
CH4
Condensed
Line-angle
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Chapter 3
BUTANES
n-BUTANE
iso-BUTANE
Note: 1 H here
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Chapter 3
Pentanes
=>
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Chapter 3
Writing Isomers -Heptanes
1. Start with longest straight chain possible
Obviously you do not add the extra carbon to end carbon!!!
2. Shorten chain by one carbon and add the "extra" at all possible positions, starting with left-handed side. 2-Methylhexane
2-Methylhexane
2-Methylhexane
3-Methylhexane
3-Methylhexane
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Chapter 3
3. Shorten chain by one more carbon. This gives a 5-carbon chain (pentane). Two carbons are to be added as two methyl groups or a single two-carbon group (ethyl group).
THIS is 3-methylhexane!!