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“Organic Chemistry Basics: Isomers and Stability in Depth” is available to Standard subscribers.
Beyond the textbook: counting the structural isomers of a formula and the stereoisomers of a molecule, and comparing the stability of intermediates and the acidity of compounds. The problems that JEE, NEET and A-Level Chemistry ask most, with a full timed paper.
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Counting structural isomers: Find the degree of unsaturation first. Count alkane skeletons by shortening the longest chain. The number of alkyl groups C1 to C5 is 1, 1, 2, 4, 8 and counts alcohols, halides, amines, acids and esters fast.
Counting stereoisomers: Each feature gives a choice. Different centres give 2 to the power n stereoisomers. Alike ends bring meso forms and cut the count. Rings and double bonds add features. Enantiomers are mirror images and diastereomers are the rest.
Stability, acidity and basicity orders: Stability is how well charge or an odd electron is spread out. Use resonance first, then inductive and hyperconjugation. Carbocations: tertiary is best. Carbanions: the opposite. Acids, bases and alkenes follow from the ions they form.