Organic Chemistry - Nomenclature, conventions, and rules

__Naming organic molecules – nomenclature rules:

1. __NO. of carbons in the longest chain containing the functional group

   1 = ==meth-

   ==2 = ==eth-

   ==3 = ==prop-

   ==4 = ==but-

   ==5 = ==pent-

   ==6 = ==hex-

   ==7 = ==hept-

   ==8 = ==oct-

   1. ==Count along the carbon chain such that the functional group has the lowest number

2. Functional groups (a prefix or a suffix)
   Alkanes = ==-ane==Alkenes = ==-ene==Halogenoalkanes = ==bromo-==, ==chloro-==, etc.

   Alcohols = ==-anol== or ==hydroxy-

   ==Nitrile = ==-onitrile

   ==Ketones = ==-anone

   ==Carboxylic acids = ==-anoic acid

   ==Esters: alcohol name first, acid name second e.g., methyl ethanoate

3. Side/branched chains: Use NO. of carbons, + suffix “-yl”

   CH3 = ==methyl

   ==CH3CH2 = ==ethyl

   ==CH3CH2CH2 = ==propyl

4. ==Position of functional group or side chain:

   1. The number needs to indicate which carbon the group is on.
   2. The number is placed before the functional group name.
   3. The lowest number is used if there is a choice. If more than one group: use the lowest combination of numbers.
   4. Carboxylic acids and aldehydes are always on the “first” carbon.

5. More than one of the same things?
   ==2 = di====3 = tri====4 = tetra

6. ==Commas and dashes: a comma is put between numbers and dashes go between numbers and words. Nothing is needed between words

__Writing Formula:

__When writing the structural formula, use brackets to show when a functional group is branched off

e.g., CH3CH(CH3)CH2CH3

• (brackets show side-chain)

Skeletal formula: only shows the bonds between carbon atoms (looks like a stick figure)

Molecular formula: the exact amount of each atom in the molecule

Empirical formula: the simplest ratio of the amount of each atom in the molecule

__Conventions in Organic Chemistry:

__Curly arrow:

• Movement of a single electron:
• Movement of an electron pair: then…

__Terminology of carbon-containing functional groups:

• __Primary carbons – carbons bonded to one other carbon
• Secondary carbons – carbons bonded to two other carbons
• Tertiary carbons – carbons bonded to three other carbons
• Quaternary carbons – carbons bonded to 4 other carbons

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