Organic Chemistry: Nomenclature, Synthesis, and Reactions of Aldehydes and Ketones, Study notes of Organic Chemistry

Download Organic Chemistry: Nomenclature, Synthesis, and Reactions of Aldehydes and Ketones and more Study notes Organic Chemistry in PDF only on Docsity! Chapter 9: _____________________________ functional group: a) aldehyde b) ketone I. Nomenclature (9.1) A) Aldehydes 1. IUPAC Select longest C chain that contains the carbonyl C alkane + al alkene + al CH3C O H CH3CH2CH2CHO Substituted Aldehydes a) Number chain starting with the carbonyl C as 1 HCCH2CHCH3 O CH3 b) Carbonyl has precedence over OH: Named as aldehyde (-al) with OH as a substituent HCCH2CH2OH O 1 2. Common Names H C H O H C CH3 O CHO (ethanal) = (methanal) = (Skip naming cyclic aldehydes = alkane + carbaldehyde) B) Ketones 1. IUPAC Select longest C chain that contains the carbonyl C alkane + one CH3CCH3 O O If C chain > 3C – indicate position of carbonyl - number chain carbonyl C gets lowest possible # CH3CCH2CH2CH3 O CH3CHCH2CCH2CH3 O Br CH3CCH2CH2OH O Q: Why don’t you need to indicate the position of the carbonyl in aldehydes? 2 II. Synthesis of Aldehydes and Ketones (9.3) 1. Oxidation of Alcohols (Chapt 7) 2o Alcohol Jones Ketone 1o Alcohol Aldehyde PCC 2. Aromatic Acylation → Ketones (Chapt 4) 3. Hydration of Alkynes → Ketones (Chapt 3) III. The Carbonyl Group (9.5) Bonding Geometry C O R R C O R R Electronic Properties C O R R Resonance C O R R 5 IV. Reactions A. B. C. D. Characteristic Rxn of carbonyl: A. _________________________________ (9.6) General Rxn Mech: If good Nu If weak Nu - 6 Reactivity of Aldehydes vs Ketones toward Nu ** 1. __________ C O R R C O R H C O carbonyl polarization: 2. _______________ alkyl groups : Ketones vs Aldehydes 7 2. Addition of ______________________ CH3 C CH3 O Acetals as ________________________ equilibrium (reversibility) important R' C H O + 2 ROH H+ R' C H OR OR + H2O add excess ROH add excess H2O CH3CCH3 O CH3CH2OH (xs) H+ CH3CH2-C-CH3 OCH3 OCH3 H2O H+ 10 Example of Use as Protecting Group Want: HC C BrCH2C-H O + SN2 But: HC C BrCH2C-H O + Solution: BrCH2C-H O 11 3. Addition of Grignard Reagents (9.9) → General: Mech. C O + RMgX The type of alcohol you make depends on the type of carbonyl you start with. Formaldehyde → 1. CH3MgBr 2. H2O, H + Other aldehydes → C O CH3CH2 H 1. CH3MgBr 2. H2O, H + Ketones → C O CH3CH2 CH2CH3 1. CH3MgBr 2. H2O, H + 12 B. ________________ of Carbonyl  Alcohols (9.12) oxidation reduction CH3CCH3 O CH3CHCH3 OH 1) ____________________ Ex. Sources of: C OMech. H AlH3Li O 1. NaBH4 2. H2O CH3CH=CHC O H 1. LiAlH4 2. H2O Note: Ex. 2) ___________________ CH3CH=CHC O H H2 Pt Ex. 15 Aldehydes and ketones both react similarly with reducing agents  alcohols ? with oxidizing agents C. Oxidation of Carbonyls (9.13) Oxidize = gain O, lose H Aldehyde vs Ketone C O R H C O C C Reagents CH2=CHCH2CH O Ag2O ex. 16 Commercial Use: to silver mirrors and glass Also during rxn Tollen’s Silver Mirror test Ag2O aldehyde ketone 17 3) _______________________________ (9.17) rxn in which enolate anion is used as a C nucleophile & attacks another carbonyl CH3CH O + CH3CH O Ex. Mech: form anion Nu attack abstract H from H2O Ex. Predict the product: CH3CH2CH O OH- 2 20 9.18 Mixed Aldol Condensation can use two different carbonyl compounds Limitation ex. Predict the product: CH3CH O + OH- CH3 C CH3 CH3 C O H 21 V. Physical Properties (9.5) Types of Intermolecular Forces 1. 2. 3. For similarly sized “small” molecules: A. BP of aldehydes and ketones Similar size? CH3CH2CH2CH3 CH3CH2CH O CH3CCH3 O CH3CH2CH2OH BP Trend: 22