Enamines Stork enamine synthesis

Some secondary amines commonly used in the Stork enamine synthesis. 

Carbohydrates Ultimately, carbohydrates cire the product of photosynthesis, the process in plants that combines carbon dioxide, water, and energy with chlorophyll and other biomolecules to produce Ccirbohy-drates and release oxygen gas. The major carbohydrate formed during photosynthesis is glucose. Plants and animals sometimes combine simple carbohydrates such as glucose into more complicated carbohydrates such as stcirch, glycogen, and cellulose. 

Lipids Lipids cire biomolecules that are insoluble in water but soluble in low-polarity organic solvents such as Et20 and CHCI3. Lipids include fats and oils, as well as many other biologically important molecules (think waxes and steroids). 

Nucleic acids, which are polymers of nucleotides, are another class of biomolecules, but they re beyond the scope of this book for more info about nucleic acids, refer to a more advanced text, such as Biochemistry For Dummies (written by us and published by Wiley). 

Carbohydrates are either polyhydroxy aldehydes and ketones or substances that form these compounds after hydrolysis. The general formula is [C (H20) ]. Normally carbohydrates occur as hemiacetals or acetals (hemiketals or ketals). 

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Enamines like enolates are alkylated when treated with reactive alkylating agent, a-Substituted enamines can be converted into aldehydes and ketones by acid-catalyzed hydrolysis. Thus, in the three-step process, alkylation of aldehydes and ketones may be carried out via enamines (Stork enamine synthesis) (Scheme 3.19). 

When the nitrogen of the substrate contains a chiral R group, both the Stork enamine synthesis and the enamine salt method can be used to perform enantio-selective syntheses. " ... 

Stork enamine synthesis takes advantage of the fact that an aldehyde or ketone reacts with a secondciry cimine to produce an enamine. Enamines cire resonance stabilized (see Figure 15-25) and have multiple applications. In the first resonance structure, the nitrogen is the nucleophile, while in the second resonance structure, the Ccirbanion is the nucleophile. Some commonly used secondary amines, pyrrolidine, piperidine, and morpholine, are shown in Figure 15-26. 

Stork Enamine Synthesis A reaction leading to the formation of an a-alkyl or a-carbonyl compound from an alkyl or aryl halide reacting with an enamine. 

When the nitrogen of the substrate contains a chiral R group, both the Stork enamine synthesis and the enamine salt method can be used to perform enantiose-lective syntheses. The use of A-proline can generate a chiral enamine in situ, thus allowing alkylation to occur, giving alkylated product with good enantioselec-tivity,. The reaction has been done intramolecularly. ... 

An intramolecular variant of the Stork enamine synthesis was utilized during the asymmetric total synthesis of (-)-8-aza-12-oxo-17-desoxoestrone by A.I. Meyers et al. ... 

Stork enamine synthesis Alkylation of enamines with alkyl halides to afford a-alkylated aldehydes or ketones. 444... 

The reaction of electrophiles with tertiary enamines can be formulated as having several stages and is illustrated by equation 1. The fact that C-substitution can be forced, even when initial reaction occurs at the enamine nitrogen, is one of the synthetic virtues of the Stork enamine synthesis . 

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