Preview Comprehensive Organic Chemistry for IIT JEE main and Advanced by Amitava Mazumder (2006) Preview Comprehensive Organic Chemistry for IIT JEE main and Advanced by Amitava Mazumder (2006) Preview Comprehensive Organic Chemistry for IIT JEE main and Advanced by Amitava Mazumder (2006) Preview Comprehensive Organic Chemistry for IIT JEE main and Advanced by Amitava Mazumder (2006) Preview Comprehensive Organic Chemistry for IIT JEE main and Advanced by Amitava Mazumder (2006)
Notion Press Old No 38, New No McNichols Road, Chetpet Chennai – 600 031 First Published by Notion Press 2017 Copyright © Amitava Mazumder 2017 All Rights Reserved eISBN 978-1-948352-50-5 This book has been published with all reasonable efforts taken to make the material error-free after the consent of the author No part of this book shall be used, reproduced in any manner whatsoever without written permission from the author, except in the case of brief quotations embodied in critical articles and reviews The Author of this book is solely responsible and liable for its content including but not limited to the views, representations, descriptions, statements, information, opinions and references [“Content”] The Content of this book shall not constitute or be construed or deemed to reflect the opinion or expression of the Publisher or Editor Neither the Publisher nor Editor endorse or approve the Content of this book or guarantee the reliability, accuracy or completeness of the Content published herein and not make any representations or warranties of any kind, express or implied, including but not limited to the implied warranties of merchantability, fitness for a particular purpose The Publisher and Editor shall not be liable whatsoever for any errors, omissions, whether such errors or omissions result from negligence, accident, or any other cause or claims for loss or damages of any kind, including without limitation, indirect or consequential loss or damage arising out of use, inability to use, or about the reliability, accuracy or sufficiency of the information contained in this book Preface Purpose and mission This book is intended to become a useful companion for the Engineering Test Aspirants of India in areas of accuracy, usability, relevance for the examination, flexibility, and connection with their needs This text would evolve over the years and should eliminate much of the cost for owning several costly top-quality college-level organic chemistry texts, by putting together the relevant material in one book, and, we hope would contribute eventually to the building of our nation by creating top quality minds Author The author of this book, Amitava Mazumder, had finished his graduation in Engineering from N.I.T – Durgapur and his Post Graduation in Industrial Metallurgy from Jadavpur University-Kolkata, and has more than ten years experience of teaching Chemistry to the Engineering Entrance Test aspirants in Delhi, Kota and Dubai He presented his thesis for International Conference for Manufacturing in Dhaka, Bangladesh in 2000 and published his paper in the proceedings of the same conference Amitava intends that this book should keep on evolving by contributions from all in the student and teaching community and therefore welcome comments and suggestions so that he can better serve his dream of creating well informed and thoroughly prepared engineering aspirants About this book One of the main difficulties students have with organic chemistry is organizing the information in their minds An engineering entrance aspirant very quickly will learn over hundreds of chemical reactions Consequently, it is vital that students take time to not only organize the information, but also to understand it Indeed, excellent organic chemistry professors will tell, contrary to popular belief, one not really need to memorize anything for organic chemistry, instead, one simply needs to understand it By truly learning something, rather than memorizing it, the students will be able to apply concepts beyond what they are memorizing This book intends to help the students in getting into the core concepts of Organic Chemistry and encourage them to always ask why something is the case This book would direct them to inquire, and find out the answer By taking this approach the student will enrich the learning experience, and the information will be “locked” in their mind so that they are able to face the challenging problems of entrance examinations Contributions Amitava has always endeavored to research facts and interpretations available in the best Organic Chemistry books, and, present it to the students of India in a form that they would understand thoroughly He has freely learned from the writings of eminent authors in this field and for this book he has drawn from this knowledge so that the students can get a comprehensive source of organic chemistry for entrance examinations in this book Amitava therefore thanks all those authors, and would always be indebted to them for enrichingAmitava’s knowledge of the very vast field of organic chemistry Specifically he is thankful to his parents who have always nurtured and motivated him to follow his dream, his wife Swati & siblings Sudip, Swagata, Sudeshna, nephew Rishi who have stood by him in the most difficult times A special thanks to Mr.R.K Verma, founder director of Resonance Institute of Kota, who has always motivated Amitava to selflessly contribute to the welfare of the students Amitava is also deeply indebted to Mr Arijit Das, who has motivated from the beginning itself and who has designed the front and back cover of the book as well as the preface, Prof U C Ghosh, Prof K L Ghatak (Presidency College, Kolkata), who were his teachers, Dr R.C Sharma, Mr Lokesh Khandelwal, Dr Bikramjit Basu (IIT-Kanpur), Mr.R.K Bandopadhyaya, Dr.V P Mittal, Mr Pramod Rana, Mr.Ramashish Paul for always encouraging Amitava to author this book, and for guiding his vision of serving the ambitions of the students of India Finally In spite of our best efforts this first edition may contain several inadvertent errors and misprints I hope that you would sincerely pardon the author for the same andAmitava looks forward to your sincere contributions to keep on improving this effort After all a knowledgeable Indian student is a pride for all ofus -Amitava Mazumder May 2006 Acknowledgement My mom Mrs Kalyani Mazumder, dad Late Mr Suprasanna Kumar Mazumder, wife Swati and kids Anuska and Aayush; Mr Mahesh Patil (IPS), Mrs Archana Patil, Mr Pratap Singh (Commisioner, IRS), my sibling Sudip, Swagata, Dr Sudeshna, Prof Bikramjit Basu (Prof IISc, Bangalore), Isha Sethi, Mr Sanjeev Sethi (cfo, Star TV), Prof Asish Arora (Physics), Mr R.K Verma ( MD, Resonance), Mr Jitendra Panda (MD, Peerless, Kolkata) Mrs Sumi, Pratik, and Projwal; thanks to Ms Gabriela Caster and Ms Preethi.K of Notion Press and their team as a whole Contents 1) IUPAC Nomenclature 2) General Organic Chemistry 3) Isomerism 4) Nucleophilic substitution and elimination 5) Alkane 6) Alkenes 7) Alkynes 8) Alkyl halide, Grignard's reagent 9) Alcohol 10) Ether (cyclic, acyclic), thioether 11) Aromatic electrophilic substitution 12) Aromatic hydrocarbons 13) Aromatic halides 14) Phenol 15) Carbonyl compounds 16) Carboxylic acids 17) Carboxylic acid derivatives 18) Aliphatic and aromatic nitro compounds 19) Amines 20) Carbohydrate 21) Amino acid 22) Polymer 23) Practical organic chemistry 24) Reagent list Exercises IUPAC Nomenclature In the early days an organic compound was named as per their origin or their characteristic property These names are called as common name or trivial name Take an example like formic acid (HCOOH) It originates from ant & the latin name of ant is formicium and also it behaves like an acid Thus the name formic acid is given But with increasing number of organic compounds & complexities name, scientific tools were developed by an international body, famously called as International Union of Pure and Applied Chemists in the year 1947 Since then this IUPAC system has been followed to name the compound We will observe while naming the organic compounds that in some cases trivial names or common name’s have been retained by IUPAC Paraffins or alkanes (general formula CnH 2n + 2) : First look that there can be several types of C and H in the simplest alkane There are the compounds made up single bond between C–atoms (due to its catenation property) 1° C means that C, which is attached to only one C Like wise 2°, 3°, 4° and 1°, 2°, 3° H means that corresponding H-atoms are attached to 1° C, 2° C, 3° C respectively There cannot be any 4° H Let us introduce the functional groups & their names available in organic chemistry in table-1 Table-1 Names and formulae of functions and classification of acyclic compounds with examples(G=general, I=IUPAC name) Nucleophilic addition although is very difficult but at 160° – 200°C and in presence of methyl vinyl ether is formed Methyl vinyl ether is a member of the polymoer polynyl ether Alkyl halide The alkyl halides have general formula CnH2n +1X, where X denotes F, Cl, Br, I Preperation: Very good source of alkyl halide is alkane, which we have already discussed in the chapter of alkane We will discuss other methods of preparations below From alcohol: For alcohols –OH is a bad leaving group therefore we first convert it into a good leaving groups like H2O, etc using H+, ZnCl2 (catalytic amount), PBr3, SOCl2, PCl5 etc respectively and the X (halide) attacks to give RX Mechanism for (b) already have been discussed Mechanism for (a) is, The mechanism is SN1 where dehydration is slow step and is the effective nucleophile at high concentration For alcohol, CH3OH proceeds through SN2 mechanism As the Cl– is a poor nucleophile than Br–, I– Therefore HCl does not react with 1°, 2° alcohol unless ZnCl2 is used and produces a better leaving group than H2O Mechanism: Mechanism: From ether: Ethers can only react with acid not with base or nucleophile For the cleavage of R–O bond and R’ – O bond concentrated HI, HBr, H2SO4 under heating carry out the change Mechanism: Hunsdicker or Borodine–Hunsdicker reaction: Mechanism : Mechanism: For an enyne, it takes -C with respect to the triple bond preferab ly Also trace amount of Br• only picks up allylic–H as the bond dissociation energy is low for allylic C–H Physical Properties : Alkyl halides have only dipole-dipole attraction Therefore b.p., density has the order R – I > R – Br > R – Cl For R, 1° > 2° > 3° as b.p order (among isomers) They burn with green edged flame Alkyl halides are insoluble in water but soluble in alcohol Chemical reactions: As far as the types of chemical reactions are concerned (SN, E), those already have been discussed before Some more reactions are; Grignard’s reagent Preparation : The order of reactivity of halides are, I > Br > Cl > F and RX > ArX, CH2 = CH – X Tetrahydrofuran can also be used as solvent instead of acyclic ether Physical properties : The commonly written structure of Grignard’s reagent is RMgX in which R is negatively polarized carbon and can be shown as The other experimental data regarding the structure is beyond the scope of this book Chemicial reactions: Generally the alkyl or aryl part acts as the nucleophilic as well as basic site Therefore it undergoes nucleophilic addition to carbonyl compound or other polarised multiple bond (eg – C N etc.) As it can act as a very strong base (as RH is very weak acid) Therefore whenever it finds acidic – H it picks up and the reactivity order of RMgX is, (1) Grignard’s reagent acting as a base; The mechanism as shown above is predicted because (1) two molecules of Grignard’s reagent is involved in which second molecule acts as the Lewis acid and (2) Addition of MgX2 speeds up the reaction, [Therefore RMgX can be thought of the mixture of R2Mg + MgX2 As the reactant concentration increases, rate of nucleophilic addition also increases While reaction to carboxyl compounds shown above always is 1, 2, It can be also 1, addition Exception to the normal 1,2 addition reactions are also found For Example, Case –1 : GR having H-atoms on their P- carbon atom (RCH2CH2MgX) tends to reduce Look at I, in which instead of alkyl group with bp electrons hydride transfer takes place to the C + and thereby ketone reduces to 2° alcohol Case- : Sterically hindered ketones having to enols and GR converts to R–H - H atom tend to be converted The above addition reactions are irreversible in nature (3) Reactions with where Z = Cl, OEt etc For example ; Therefore moles of GR are required for ester, acid halides etc to produce 3° alcohol upon hydrolysis Recently GR are replaced by RLi, ArLi etc as they prefer to give (1, 2) addition product compared to (1, 4) addition product and gives normal addition products with sterically hindered ketones For example- with acid ... this field and for this book he has drawn from this knowledge so that the students can get a comprehensive source of organic chemistry for entrance examinations in this book Amitava therefore thanks... organize the information, but also to understand it Indeed, excellent organic chemistry professors will tell, contrary to popular belief, one not really need to memorize anything for organic chemistry, ... Mr Lokesh Khandelwal, Dr Bikramjit Basu (IIT- Kanpur), Mr.R.K Bandopadhyaya, Dr.V P Mittal, Mr Pramod Rana, Mr.Ramashish Paul for always encouraging Amitava to author this book, and for guiding