ORGANIC CHEMISTRY
CLASS 12 • HIGH-VALUE EXAM NOTES
A clean, handwritten-inspired revision notebook
HOW TO USE THESE NOTES
Read the concept map first → learn the key rule → rehearse the reaction or comparison → finish with the
one-page memory sheet.
SOURCE FIDELITY
These notes are organized from the uploaded spoken lecture transcript only. Filler has been removed. Where the
transcript is unclear or incomplete, the notes flag the gap rather than silently supplying an answer.
VISUAL KEY
Mark Meaning
Blue heading / underline Core concept or topic
Teal box Key point / remember
Yellow box Memory aid or shortcut
Red box Common mistake / caution
Reaction arrow → Transformation or process
Keep the rules close. Practise naming, mechanisms and reaction recognition actively.
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,ORGANIC CHEMISTRY • SOURCE-BASED REVISION
01 | IUPAC NOMENCLATURE
The naming framework: S – R – B – F
S R B F
Substituent Root word Bond Functional group
• Substituent: side groups such as halogens and alkyl groups.
• Root: number of carbons in the parent chain.
• Bond: single = -an-; double = -en-; triple = -yn-.
• Functional group: determines the principal suffix when selected as the highest-priority group.
Root words to memorise
C atoms Root C atoms Root
1 meth- 6 hex-
2 eth- 7 hept-
3 prop- 8 oct-
4 but- 9 non-
5 pent- 10 dec-
Functional-group endings named in the lecture
Group Suffix / example
Alcohol (–OH) -ol; butanol, butan-2-ol
Aldehyde (–CHO) -al; propanal, pentanal
Ketone (>C=O) -one; propanone / 2-propanone
Carboxylic acid (–COOH) -oic acid; propanoic acid
C=C / C≡C -en- / -yn-; ethene / ethyne
Numbering and naming: do it in this order
2. Number for
1. Longest 3. Identify 4. Assemble
lowest priority
continuous chain substituents the name
locant
• The parent chain should include the principal functional-group carbon and the multiple bond
where applicable.
• The lecture’s priority order for numbering is: principal functional group → multiple bond →
substituents.
• Use position numbers; alphabetise substituent prefixes (the lecture example places bromo before
chloro).
• Repeated substituents use di-, tri-, etc. Separate numbers with commas and numbers/words with
hyphens.
MEMORY TRICK
S–R–B–F = Substituent → Root → Bond → Functional group. Use it as a build-order reminder, but apply the
lecture’s priority rules when choosing the parent and numbering.
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, ORGANIC CHEMISTRY • SOURCE-BASED REVISION
01 | NOMENCLATURE — PRIORITY & RING
TERMS
Functional-group priority given in the lecture
Higher → lower Group
1 Carboxylic acid (–COOH)
2 Sulfonic acid (–SO₃H)
3 Acid anhydride
4 Ester
5 Acid chloride
6 Amide (–CONH₂)
7 Nitrile (–C≡N; called cyanide in the lecture)
8 Aldehyde (–CHO)
9 Ketone (>C=O)
10 Alcohol (–OH)
11 Amine (–NH₂)
• The highest-priority group is used as the principal suffix; lower-priority groups may be prefixes.
• Prefix examples in the source: hydroxy- for an alcohol group when it is not principal;
oxo-/keto-type wording is also mentioned for carbonyl groups.
Benzene-ring position language
Relationship Meaning
ortho (o-) 1,2-substitution pattern
meta (m-) 1,3-substitution pattern
para (p-) 1,4-substitution pattern
• Common aromatic names mentioned include aniline and cresol; cresol is a methyl-substituted
phenol.
COMMON MISTAKE
Do not count an oxygen atom as a carbon in the parent chain. Select the actual continuous carbon chain; a
functional group may sit at its end.
Bond-line structures: fast reading
Every corner / endpoint Carbon-bound H atoms A branch from a corner
= carbon are omitted = substituent
• Count corners and endpoints, then infer the hydrogens needed for carbon’s four bonds.
• A five-carbon chain with only single bonds is pentane; changing the bond type changes the bond
infix.
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