GOC-2 Lecture 13 (Part 4) | Alcohol → RCl via PCl₅, PX₅ & SOCl₂ | SN1 vs SN2 (SNi) | JEE NEET скачать в хорошем качестве

GOC-2 Lecture 13 (Part 4) | Alcohol → RCl via PCl₅, PX₅ & SOCl₂ | SN1 vs SN2 (SNi) | JEE NEET

GOC-2 Lecture 13 (Part 4) | Alcohol → RCl via PCl₅, PX₅ & SOCl₂ | SN1 vs SN2 (SNi) | JEE NEET | ChembyKKSir ⸻ #GOC2 #AlcoholReactions #PCl5 #PX5 #SOCl2 #SN1 #SN2 #SNi #RetentionOfConfiguration #SubstitutionReaction #AlkylHalides #ReactionMechanism2 #OrganicChemistry #Class12OrganicChemistry #JEE2026 #NEET2026 #JEEAdvanced #ChemistryByKKSir #ChembyKKSir ⸻ Namaste Dear Students 🙏 Welcome to GOC-2 Lecture 13 (Part 4) — a short but conceptually important lecture completing the remaining portion of reactions of alcohols with different halogenating reagents. After understanding alcohol reactions with HX and BX₃ in previous parts, this lecture focuses on the most practical and exam-relevant methods of converting alcohols into alkyl chlorides. In this lecture, I — Krishna Kumar Sah (ChembyKKSir) — have explained clearly: 🔹 Reaction of Alcohol with PCl₅ / PX₅ • Conversion of ROH → RCl • Basic substitution pathway • Role of phosphorus halides • Mechanistic insight (SN1/SN2 tendency depending on substrate) 🔹 Reaction of Alcohol with SOCl₂ (Most Important) • Why SOCl₂ is the best reagent to prepare RCl from alcohol • Clean reaction with gaseous by-products (SO₂, HCl) • Mechanistic difference based on conditions ✔ With Pyridine → SN2 mechanism – Backside attack – Inversion of configuration ✔ Without Pyridine (Non-polar solvent) → SNi mechanism (Nucleophilic Substitution Internal) – Retention of configuration – Unique internal return mechanism explained 🔹 Key Concept • Role of solvent in deciding mechanism • Stereochemical outcome (Retention vs Inversion) • Comparison with HX reactions 🔥 Why This Lecture Is Important: • Frequently asked mechanism-based concept in JEE Advanced • SOCl₂ questions are common in stereochemistry problems • Helps in understanding configuration retention vs inversion • Completes alcohol → alkyl halide conversion logic This lecture connects with the complete GOC-2 framework: SN1, SN2, Carbocation stability, Leaving group ability, Solvent effect, Stereochemistry, Substitution vs elimination, and Haloalkane preparation methods. If you clearly understand SOCl₂ reaction with and without pyridine, you will never be confused in stereochemistry-based substitution questions 🔥