Naming, acid anhydrides aldehydes

Classically, this separation of roles was accomplished by utilizing substrates that differed drastically in their ability to form enolate anions. In fact, the various name reactions mentioned above are distinguished not by basic differences in mechanism, but by the nature of the components preferentially utilized as substrates. For example, in the Perkin reaction, the condensation of an aromatic aldehyde with an aliphatic acid anhydride is based on the fact that the electrophilic component, e.g. benzaldehyde, lacks a-hydrogens and therefore is incapable of forming an enolate. At the same time the utilized electrophile, acetic anhydride, contains a carbonyl group with reduced propensity to interact with nucleophiles. Hence, it is incapable of undergoing self-condensa-... 

In this zinc-promoted joining reaction (as the authors named it) acetic acid anhydride behaved in a similar manner to ketones and aldehydes ... 

The spirobenzylisoquinoline 171b derived from berberine (15) (Section IV,A,1) was oxidized with m-chloroperbenzoic acid to the /V-oxide 389, which was treated with trifluoroacetic anhydride to afford dehydrohydrastine (370) in 56% overall yield (Scheme 71) through the Polonovski reaction (187). Holland et al. (188,189) reported the reverse reaction from dehydrophthalides to spirobenzylisoquinolines, namely, 370 was reduced with diisobutylalu-minum hydride to give a mixture of two diastereoisomeric spirobenzylisoquinolines 320 and 348 via the enol aldehyde. This reaction was applied to synthesis of various spirobenzylisoquinoline alkaloids such as (+)-sibiricine (352), ( + )-corydaine (347), (+ )-raddeanone (354), ( )-yenhusomidine (359), (+ )-ochrobirine (343), and ( )-yenhusomine (323). 

Name an aromatic compound, a phenol, an aldehyde, a ketone, a carboxylic acid, an acid chloride, an anhydride, an ester, an amide, a nitrile, and a carboxylic acid salt. (Problems 12.21, 12.31, and 12.33)... 

For bringing about the first reaction the following-named substances may be used as condensation agents hydrochloric acid, acetic anhydride, as well as primary and secondary amines (ethyl amine, diethyl amine, piperidine, and others). For the second reaction the bases mentioned may be used. A small quantity of one of these may produce la rge quantities of the condensation product this is a case of a so-called continuous reaction. It is probable that the amine reacts first with the aldehyde, water being eliminated 1... 

Substances discovered by Gerhardt include cumene, cuminol as the aldehyde of cumic acid, and cymene, styrene, anilides, sulphanilic acid, acetanilide, and the anhydrides of monobasic organic acids (1852, see p. 454). He introduced the names phenol, borneol, and glucoside. After Laurent s work on phenol (see p. 389) Gerhardt prepared it by heating salicylic acid with lime and showed that it is not a true acid (acide phenisique) but is related to the alcohols. In his work on anilides he represented oxamide, which the discoverer Dumas had correctly formulated as an amide, + N H, as containing the imide group NH, viz. + = +... 

Another amino acid synthesis is called the azlactone synthesis. Remember from before that an azlactone is an oxazolone (see 95). When glycine (52) is converted to its AT-benzoyl derivative (112 known as hippuric acid) by reaction with benzoyl chloride, treatment with acetic anhydride (AC2O) gives the azlactone 113. This is the reaction presented in the preceding section (see compormd 95). Compound 110 has the common name of hippuric acid azlactone. As with the thiohydantoin, the -CH2- unit in 113 is susceptible to an enolate anion condensation reaction with aldehydes (Chapter 22, Section 22.7.2), and reaction with 2-methylpropanal in the presence of pyridine gives azlactone 114. Catalytic hydrogenation of the alkene unit (Chapter 19, Section 19.3.2) and acid hydrolysis lead to the amino acid leucine (55). 

Scheme 9.6. A cartoon representation of the enzyme (named glyceraldehyde-3-phosphate dehydrogenase, EC 1.2.1.12) catalyzed oxidation of the aldehyde glyceraldehyde-3-phosphate to the carboxylic acid-phosphoric acid mixed anhydride, 1,3-bisphosphoglycerate (which can be hydrolyzed to the corresponding carboxyhc acid and phosphoric acid). Start in a clockwise direction from the npper left.

In this chapter, we will be discussing the chemistry of carboxylic acids, esters, acyl halides, anhydrides, and amides. This is dominated by substitution, where one group is exchanged with another. Substitution is NOT possible for aldehydes and ketones, as you can t displace H or — they are hopeless leaving groups. First, let s review some nomenclature. The suffix for carboxylic acids is -oic acid and the carbonyl of the acid is always numbered as C-1. The acid takes precedence over most other functional groups. Some examples are shown in Figure 15.1. Notice that when we have both a ketone and an acid in the molecule, it is named as a carboxylic acid, and the ketone is described as oxo. ... 

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