Xiaoping Sun - Organic Mechanisms

8 Chapter 8FIGURE 8.1 (a) Addition of a strong nucleophile to a ketone or aldehyde; (b)...FIGURE 8.2 Mechanism for the hydroxide base catalyzed hydrolysis of ester (e...FIGURE 8.3 Acid and base catalyzed hydration of ketone or aldehyde.FIGURE 8.4 Mechanism for oxygen exchange between acetone and water.FIGURE 8.5 Mechanism for acid catalyzed nucleophilic addition of methanol to...FIGURE 8.6 Acid catalyzed nucleophilic addition reactions of various alcohol...FIGURE 8.7 Acid catalyzed reaction of an ester‐aldehyde with methanol, follo...FIGURE 8.8 The intramolecular nucleophilic addition of 6‐hydroxyl‐2‐heptanon...FIGURE 8.9 Cyclic structures and mutarotation of D‐glucose: the intramolecul...FIGURE 8.10 Cyclic structures and mutarotation of D‐fructose: the intramolec...FIGURE 8.11 Formations of cyclic structures of five‐carbon and six‐carbon su...FIGURE 8.12 Mechanism for acid catalyzed nucleophilic addition of an amine t...FIGURE 8.13 Reactions of a ketone or aldehyde to various compounds containin...FIGURE 8.14 Mechanism for reaction of a secondary amine with a ketone (cyclo...FIGURE 8.15 The enzymatic mechanism for conversion of fructose‐1,6‐bisphosph...FIGURE 8.16 Mechanism for nucleophilic addition of borohydride to a ketone o...FIGURE 8.17 Mechanism for nucleophilic addition of aluminum hydride to a ket...FIGURE 8.18 Structures of NAD(P) +and NAD(P)H (biological hydride donor).FIGURE 8.19 Mechanism for lactate dehydrogenase (LDH) catalyzed homolactic f...FIGURE 8.20 Structures of FAD and FADH 2(biological hydride donor).FIGURE 8.21 Reaction of a carboxylic acid with thionyl chloride.FIGURE 8.22 (a) Fischer esterification and reaction mechanism; and (b) react...FIGURE 8.23 Formation of a lactone by the entropy‐driven intramolecular este...FIGURE 8.24 (a) Structure of p ‐dodecylbenzenesulfonic acid (DBSA); and (b) t...FIGURE 8.25 The p ‐dodecylbenzenesulfonic acid (DBSA) catalyzed esterificatio...FIGURE 8.26 Formation of a cyclic carboxylic anhydride (succinic anhydride) ...FIGURE 8.27 Nucleophilic addition of nBuLi to a carboxylic acid.FIGURE 8.28 Nucleophilic acyl substitution reactions of an alcohol with an a...FIGURE 8.29 Mechanism for acid catalyzed esterification reaction of salicyli...FIGURE 8.30 Nucleophilic acyl substitution reactions of a primary amine with...FIGURE 8.31 Nucleophilic acyl substitution reaction of a primary amine with ...FIGURE 8.32 Mechanisms for acid and base catalyzed transesterification.FIGURE 8.33 Synthesis of biodiesel from corn oil.FIGURE 8.34 Mechanism for the formation of methyl ester of fatty acids (biod...FIGURE 8.35 The hydrolytic peptide bond cleavage in proteins catalyzed by se...FIGURE 8.36 The catalytic mechanism for trypsin (a serine protease).FIGURE 8.37 The reaction profile for the trypsin catalyzed hydrolytic cleava...FIGURE 8.38 Lipase catalyzed hydrolysis of triacylglycerol to fatty acids.FIGURE 8.39 Enzymatic mechanism for hydrolysis of triacylglycerol catalyzed ...FIGURE 8.40 Reductions of (a) acyl chlorides, carboxylic anhydrides, and est...FIGURE 8.41 Mechanism for reduction of an amide to an amine by lithium alumi...FIGURE 8.42 Mechanism for cyanide catalyzed nucleophilic addition of benzald...

9 Chapter 9FIGURE 9.1 Molecular orbitals formed due to the hyperconjugation between the...FIGURE 9.2 Formation of the enolate from a carbonyl compound and its equilib...FIGURE 9.3 Crystal structure of lithium enolate of 2,2‐dimethyl‐2‐butanone....FIGURE 9.4 Regiochemistry for deprotonation of unsymmetrical ketones by LDA ...FIGURE 9.5 Occupied molecular orbitals for the three‐center, four‐electron b...FIGURE 9.6 Alkylation of carbonyl compounds via enolates and primary alkyl h...FIGURE 9.7 Alkylation of carbonyl compounds via enolates and primary alkyl d...FIGURE 9.8 Alkylation of (a) an aldehyde and (b) a ketone via N,N ‐dimethylhy...FIGURE 9.9 Alkylation of a ketone via a secondary amine.FIGURE 9.10 The general mechanism for an aldol reaction of an aldehyde or ke...FIGURE 9.11 The crossed aldol condensation reactions between (a) benzaldehyd...FIGURE 9.12 Transition states and stereochemistry for the aldol reaction of ...FIGURE 9.13 The intramolecular aldol condensations to form cyclic α,β‐unsatu...FIGURE 9.14 The aldol reaction of benzaldehyde with acetic anhydride catalyz...FIGURE 9.15 The acid catalyzed aldol condensation of acetone via an enol.FIGURE 9.16 Mechanism for the ( S )‐proline catalyzed enantiomerically specifi...FIGURE 9.17 Mechanism for the ( S )‐proline catalyzed enantiomerically specifi...FIGURE 9.18 Mechanism for the ( S )‐proline catalyzed diastereoselective aldol...FIGURE 9.19 Diastereoseletive aldol reactions of (a) ( Z )‐ and (b) ( E )‐enolat...FIGURE 9.20 (a) Nucleophilic 1,2‐ and 1,4‐additions to an α,β‐unsaturated ca...FIGURE 9.21 (a) Resonance structures and (b) the occupied molecular orbitals...FIGURE 9.22 Mechanism for the Robinson annulations.FIGURE 9.23 Darzens condensation: Reaction and mechanism.FIGURE 9.24 Mechanism for Claisen condensation of an ester.FIGURE 9.25 Alkylation of a β‐ketoester via the S N2 reaction of the enolate ...FIGURE 9.26 Alkylation of a β‐ketoester via the S N2 reaction of the enolate ...FIGURE 9.27 Alkylation of a diester by reaction of the enolate with 1,4‐dibr...FIGURE 9.28 The intramolecular Claisen condensation of a 1,7‐diester and sub...FIGURE 9.29 (a) The alkoxide base catalyzed crossed Claisen condensation giv...FIGURE 9.30 Structure of acetyl‐coenzyme A.FIGURE 9.31 The enzymatic mechanism for synthesis of citrate, the first step...FIGURE 9.32 Mechanism for thiolase catalyzed Claisen condensation of acetyl‐...

10 Chapter 10FIGURE 10.1 Major types of rearrangements identified in organic reactions.FIGURE 10.2 The 1,2‐shift in a general carbocation.FIGURE 10.3 The carbocation 1,2‐shifts involved in SbF 5catalyzed isomerizat...FIGURE 10.4 The carbocation rearrangements involved in (a) electrophilic add...FIGURE 10.5 The ring expansions involved in (a) nucleophilic substitution re...FIGURE 10.6 (a) Pinacol rearrangement, (b) acid catalyzed ring‐expansion and...FIGURE 10.7 The concerted cascade carbocation 1,2‐rearrangements in a bioche...FIGURE 10.8 The 1,2‐shift in an epoxide.FIGURE 10.9 Anion‐initiated 1,2‐shifts: (a) Isomerization of a 1,2‐diketone ...FIGURE 10.10 The general mechanism for neighboring leaving group facilitated...FIGURE 10.11 Mechanism of Beckmann rearrangement, a 1,2‐shift in a nitrilium...FIGURE 10.12 Mechanism of Beckmann rearrangement involved in transformation ...FIGURE 10.13 Mechanism of Hofmann rearrangement involved in transformation o...FIGURE 10.14 Mechanism of Hofmann rearrangement for a cyclic amide.FIGURE 10.15 Mechanism of Baeyer–Villiger oxidation (rearrangement): Oxidati...FIGURE 10.16 Mechanism for Baeyer–Villiger oxidation of cyclopentanone to a ...FIGURE 10.17 The regioselectivity for the Baeyer–Villiger oxidation of unsym...FIGURE 10.18 The regio‐ and stereo‐chemistry for the Baeyer–Villiger oxidati...FIGURE 10.19 Mechanism for the acid catalyzed carbon–oxygen rearrangement of...FIGURE 10.20 Electron‐pair facilitated 1,2‐rearrangement in carbene.FIGURE 10.21 Synthesis of carbene from a ketone and stereoelectronic control...FIGURE 10.22 Stereoselective 1,2‐rearrangement of a carbene.FIGURE 10.23 Cyclization of a carbene via a 1,3‐shift.FIGURE 10.24 Photochemical 1,2‐rearrangement of an alkene to a carbene, the ...FIGURE 10.25 Claisen rearrangement (a), an analogous process to the Cope rea...FIGURE 10.26 Claisen rearrangement of a cyclic allyl vinyl ether to a γ,δ‐en...FIGURE 10.27 Claisen rearrangement of trans ‐butenyl phenyl ether to an o ‐all...FIGURE 10.28 A strong base induced Claisen rearrangement of an allyl ester t...FIGURE 10.29 The Claisen rearrangement of chorismate to prephenate in water ...FIGURE 10.30 The Claisen rearrangement of (a) 6‐β‐glycosylallyl vinyl ether ...FIGURE 10.31 The Claisen rearrangement of a naphthyl ether in water.FIGURE 10.32 Mechanism for the photochemical isomerization of trans ‐2‐stilbe...FIGURE 10.33 The photochemical rearrangement of cis ‐11‐retinol to its trans ‐...FIGURE 10.34 Synthesis of (a) the 6π 5‐organo‐1,3,2,4‐dithiadiazolium hetero...FIGURE 10.35 The photochemical rearrangement of 5‐organo‐1,3,2,4‐dithiadiazo...FIGURE 10.36 Mechanism for the concerted photochemically symmetry allowed bi...