Reaction with acetaldehyde

In contrast, transmetalation of the lithium enolate at —40 C by treatment with one equivalent of copper cyanide generated a species 10b (M = Cu ) that reacted with acetaldehyde to selectively provide a 25 75 mixture of diastereomers 11 and 12 (R = CH3) which are separable by chromatography on alumina. Other diastereomers were not observed. Similar transmetalation of 10a (M = Li0) with excess diethylaluminum chloride, followed by reaction with acetaldehyde, produced a mixture of the same two diastereomers, but with a reversed ratio (80 20). Similar results were obtained upon aldol additions to other aldehydes (see the following table)49. 

The same reaction with acetaldehyde produces carbene complex 34 with a saturated ring, i.e., an oxazolidin-2-ylidene ligand with the tosyl group replaced by methoxide. 

The similar kinetic scheme was proposed for the ozone reaction with acetaldehyde [150], The reaction rate obeys the equation... 

Halogens, See also Bromine (Br) Chlorine (Cl) Fluorine (F) Iodine (I) higher aliphatic alcohols, 2 5 in N-halamines, 13 98 reactions with acetaldehyde, 1 105 reactions with acetone, 1 163 reactions with acetylene, 1 180 reactions with alkanolamines from olefin oxides and ammonia, 2 125—126 reactions with aluminum, 2 284—285, 349-359... 

Benzophenone, directed reaction with acetaldehyde, 50, 68 1,4-Benzoquinone, 2,3-dichloro-5,6-dicyano-, (DDQ), aroma-tization with, 54, 14 Benzoylacetone, from acetophenone and acetic anhydride,... 

The reaction with acetaldehyde does not proceed further, but with the other two water is eliminated and further changes take place. 

Cyclohexyl ine, 52, 727 reaction with acetaldehyde, 50,67 Cyclooctatretraene, chlorination, 50, 36 reaction with mercuric acetate, 50, 24 CYCLOOCTENE, 1-NITRO, 50,54 CYCLOPENTANECARBOXALDE-HYDE, l-PHENYL-,51,24 Cyclopentane-1,3-dione, 52,4 CYCLOPENTYLAMINE, 1-PHENYL-, 51,45... 

Most of the peracetic acid decomposes via a cyclic reaction with acetaldehyde to form two moles of acetic acid. 

Methyl-4-penten-2-ol [Preparation of (—)-(Z)-Crotyl Bis(iso-pinocampheyl)borane and a Representative Reaction with Acetaldehyde]. ... 

Benzophenone, directed reaction with acetaldehyde, 50,68 Benzoylacetone, from acetophenone and acetic anhydride, 51, 93... 

The synthesis of substituted quinazolin-4(. 7/)-ones and quinazolines via directed lithiation has been reviewed <2000H(53)1839>, and the topic has also been briefly discussed in a more general review on the synthesis of quinazolinones and quinazolines <2005T10153>. For example, the lithiation of 4-methoxyquinazoline 312 with LiTMP followed by reaction with acetaldehyde gave only a minor amount of the 2-substituted product 313, with the major product 314 being the result of lithiation at the 8-position in the benzene ring <1997T2871>. 

Great attention was paid to oxygen atom reactions with acetaldehyde. It will be mentioned that the study of this reaction encountered greater difficulties. 

To understand the significant effect of catalyst nature, a better understanding of the main reactions, peracetic acid decomposition, and its reaction with acetaldehyde was needed. A literature -survey showed that the kinetics were not well studied, most of the work being done at very low catalyst concentration 1 p.p.m.), and there is disagreement with respect to the kinetic expressions reported by different authors. The emphasis has always been on the kinetics but not on the products obtained, which are frequently assumed to be only acetic acid and oxygen. Consequently, the effectiveness of a catalyst was measured only by the rates and not by the significant amount of by-products that can be produced. We have studied the kinetics of these reactions, supplemented by by-product studies and experiments with 14C-tagged acetaldehyde and acetic acid to arrive at a reaction scheme which allows us to explain the difference in behavior of the different metal ions. 

Peracetic Acid Decomposition. Although, by comparing the rate of peracetic acid decomposition with the rate of its reaction with acetaldehyde, we can rule out the decomposition as a major path in acetaldehyde oxidation (see below), we will discuss the possible mechanisms for the catalytic decomposition of peracetic acid. 

Incubation of tryptamine derivatives with 5-methyl-tetrahydrofolic acid and an enzyme preparation from brain gives tryptolines. Dopamine and its derivatives form related tetrahydroisoquinolines such as the product that arises from reaction with acetaldehyde (see Eq. 30-5). This product has been found in elevated amounts in alcoholics (who synthesize excess acetaldehyde), in phenylketonurics, and in L-dopa-treated patients with Parkinson disease.1136... 

Addition to formaldehyde [378] and other aldehydes [379,380] proceeds with high absolute stereoselectivity for the (5f )-configurated products (configurational reference changes for any substrate larger than formaldehyde ). In contrast, no or only a low level of relative acceptor diastereoselectivity at the chiral C-6 was determined in the reactions with acetaldehyde (6S/6R 1 1) [379] and propionaldehyde (130/131 = 1 2.4) [380] as the stereochemical probes. 

S)-amino acid. The (/ )-enriched enantiomer is present in solution after isolation of the (Si-enriched complex (Scheme 81).322 The similar quadridentate complexes of the glycinimine can be converted to the hydroxyethyl derivative by reaction with acetaldehyde. In this case the (S)-en-... 

The synthetic applications of these reactions are considered in Section 61.4.15. Reaction of copper(II) glycinate with formaldehyde in aqueous solution at pH 12 gives serine, while reaction with acetaldehyde gives a mixture of threonine and allothreonine (Scheme 35). This reaction has been extended to a variety of aldehydes to obtain longer chain /3-hydroxyamino acids.439... 

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