Pharmaceutical Organic Chemistry: A Comprehensive Textbook has been specifically developed to meet the academic and professional needs of Bachelor of Pharmacy (B.Pharm) students. Strictly aligned with the Pharmacy Council of India (PCI) syllabus guidelines (BP204T pattern), this text bridges classical organic reaction mechanisms with real-world pharmaceutical and biomedical applications. Organization and Key Features The textbook is organized systematically into five foundational units and dedicated appendices to facilitate cumulative learning: Unit I: Aliphatic Saturated Hydrocarbons & Cycloalkanes explores alkane synthesis, free-radical halogenation mechanisms, ring strain theories (Baeyer, Sachse–Mohr, Coulson–Moffitt), and their relevance to drug stability and conformational receptor binding. Unit II: Aliphatic Unsaturated Hydrocarbons & Conjugated Dienes covers electrophilic additions (Markovnikov and anti-Markovnikov regiochemistry), allylic resonance, and [4+2] Diels–Alder cycloadditions essential in natural product and steroid synthesis. Unit III: Alkyl Halides contrasts nucleophilic substitution (S_N 1 vs. S_N 2) and elimination (E1 vs. E2, Zaitsev orientation) pathways, linking alkylating reactivity directly to antineoplastic pharmacology. Unit IV: Benzene and Its Derivatives demystifies aromaticity (Hückel's rule), electrophilic aromatic substitution (EAS), and substituent orientation effects, illustrating their predictive power in Cytochrome P450 Phase I drug metabolism. Unit V: Carbonyl Compounds delivers in-depth mechanistic treatment of nucleophilic additions, named condensations (Aldol, Cannizzaro, Benzoin, Perkin, Claisen–Schmidt), and the therapeutic profiles of agents like chloral hydrate, paraldehyde, and ketoprofen.