Tiêu đề Med-RM_Chem_SP-3_Ch-14_Organic Chemistry - Some Basic Principles and Techniques (1).pdf ✅

Chapter Contents Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456  Introduction  Classification of Organic Compounds  Nomenclature System  Nomenclature of Substituted Benzene Compounds  Isomerism  General Concepts in Organic Reaction Mechanism  Reaction Intermediates  Classification of Organic Reactions  Methods of Purification of Organic Compounds  Qualitative Analysis of Organic Compounds  Quantitative Analysis Introduction The development of organic chemistry is about 200-year-old. Around the year 1780, the chemists began to distinguish between organic compounds obtained from plants and animals and inorganic compounds prepared from mineral sources. In the earlier period of development of chemistry, Berzelius, a Swedish chemist proposed that the synthesis of organic compounds within the plants and animals required some mysterious force. This force was called vital force and the theory was referred to as vital force theory. vital force theory Urea  heat Ammonium Cyanate NH CNO 4 2 NH CONH2 This synthesis gave a death blow to vital force theory and clearly demonstrated that no mysterious force was required in the formation of organic compounds in the lab. The elegant synthesis of acetic acid by Kolbe in 1845 and that of methane by Berthelot in 1856 from purely inorganic sources. The synthesis of organic compounds altogether changed the concept of organic chemistry. With the downfall of vital force theory, the term organic lost its original significance. Thus, the modern definition of the organic chemistry is the chemistry of the hydrocarbons and their derivatives. The development of electronic theory of covalent bonding gave organic chemistry a modern shape. Chapter 14 Organic Chemistry - Some Basic Principles and Techniques
2 Organic Chemistry - Some Basic Principles and Techniques NEET Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456 CLASSIFICATION OF ORGANIC COMPOUNDS Organic compounds can be classified as per chart given below. Organic Compounds Acyclic compounds (open chain compounds) e.g., hydrocarbons, alkylhalides, alkyl amines, cyanides etc Cyclic compounds (closed chain compounds) Aromatic Heterocyclic (presence of heteroatoms like N, O, S in ring) i.e., N O H Pyrrole Furan Thiophene Benzenoid Non-benzenoid e.g. Benzene Naphthalene Cyclopropylium cation Homocyclic Alicyclic (Non aromatic) , , etc. Cyclobutane Cyclo hexene Cyclopropane e.g. , , S , etc. Aromatic Alicyclic O Hydrocarbons and their Classifications Compounds of C and H only are called hydrocarbons. They are parent organic compound and all other organic compounds have been derived by replacing one or more H atoms from hydrocarbon. Hydrocarbons Acyclic (open chain hydrocarbon) Cyclic Alicyclic (cycloalkanes) Aromatic Unsaturated hydrocarbons (having= and )  Saturated hydrocarbon/Alkanes/Paraffins (GF C H )  n 2n + 2 i.e., , etc. i.e., CH3 , Toluene  Concept of n, iso and neo alkane n-alkane alkanes having C–C straight chain having only 1o and 2o C atoms. CH3 – CH2 – CH2 – CH2 – CH3 n-pentane iso-alkane alkanes having one time branching of methyl group at second last C only. i.e., CH3 CH CH3 CH2 CH3 Isopentane Neoalkane alkanes having two times branching of methylgroup at second last C only. i.e., CH3 C CH3 CH3 CH3 neo pentane
NEET Organic Chemistry - Some Basic Principles and Techniques 3 Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456  Concept of primary, secondary and tertiary C and their H atoms. In a compound like H C H C C C CH3 H H H H CH3 CH3 CH3 Primary C Secondary C Quaternary C Primary C Tertiary C H of 1o C is called Primary H H of 2o C is called Secondary H H of 3o C is called Tertiary H Some Alkyl Groups : CH3 CH2 (Ethyl) CH3 CH (Isopropyl) CH3 CH3 CH2 CH (n-Butyl) 2 CH2 CH3 CH2 CH CH (Sec-Butyl) 3 CH3 CH3 C CH3 (Tert-butyl) CH3 CH CH (Isobutyl) 2 CH3 C H4 9 CH3 C CH2 CH3 CH3 (Neo pentyl) CH2 CH CH2 (Allyl) (Vinyl) or Ph (Phenyl) or  CH2 (Benzyl) CH (Benzal) C (Benzo) CH 2 CH
4 Organic Chemistry - Some Basic Principles and Techniques NEET Aakash Educational Services Limited - Regd. Office : Aakash Tower, 8, Pusa Road, New Delhi-110005 Ph. 011-47623456 Note : Bond line notation of organic compounds can be as CH3 CH3 CH3 CH2 CH3 CH3 CH CH3 CH3 CH CH CH3 C CH C 3 CH 3 CH3 CH CH CH2 C CH Example 1 : Write the condensed formula and bond line formula for (a) CH — CH — CH — CH — O 3 2 2 H CH3 (b) H2N — CH2 — CH2 — CH2 — CH2 — COOH (c) CH — CH — CH — CH — CH — CH 3 2 22 3 Br Solution : (a) (CH3) 2CH(CH2) 2OH or OH (b) NH2(CH2) 4COOH or O NH2 OH (c) CH3CH2 CH(Br) CH2 CH2 CH3 or Br Example 2 : Expand the structure (a) (b) HO CH2CH2NH2 Solution : (a) CH3 CH3 H C C H CH3 CH3 (b) H — O — C — C — N H H H H H H