Aldehyde acetates

Amberlyst-15, acetone, H2O, 20 h, Aldehyde acetals conjugated with... 

Amberlyst-15, acetone, H2O, 20 Aldehyde acetals conjugated with electron-withdrawing groups tend to be slow to hydrolyze. The use of HCl/THF or PPTS/acetone in the following case was slow and caused considerable isomerization. A TBDMS group is stable under these conditions. ... 

The cyclization of thienylthioacetic acids " and thienylthioacet-aldehyde acetals " has been studied in connection with work on the chemistry of the thiophthenes. The cyclizations are achieved with concentrated or anhydrous usually in... 

Acetic Aldehyde.—Acetic aldehyde, CHg. COH, occurs in a number of essential oils, or their distillation waters. It is a liquid boiling at 21°. 

Glutaric anhydride, 13, r3 /-Glyceric aldehyde, 11, 50 14, 86 dl-GLYCERIC ALDEHYDE ACETAL, 11, 50, 52... 

Formyl-carbonsaure-ester werden bei geschiitzter Formyl-Gruppe (Acetal) mit Natriumboranat selektiv zum entsprechenden Hydroxy-aldehyd-acetal reduziert. Es ist... 

Dimethylamino)-benz/aldehyde-Acetic Acid-Phosphoric Acid Reagent... 

In addition to aldehydes, acetals can serve as electrophiles in Mukaiyama aldol reactions.64 Effective catalysts include TiCl4,65 SnCl4,66 (CH3)3Si03SCF3,67 and... 

The addition of alkoxides to 2-nitro-l-phenylthio-l-alkenes affords P-nitro-aldehyde acetals.276 The reaction of the same nitroalkenes with amines gives nitroenamines.270 They are important intermediates for organic synthesis and are generally prepared by the reaction of nitroalkanes with triethylorthoformate in the presence of alcohols or secondary amines.2"1 0 The methods of Eqs. 4.20 and 4.21 have some merits over the conventional methods, for variously substituted (3-nitro-aldehydes acetals or nitroenamines are readily prepared by these methods. 

The EtsSiH/tetracyanoethylene combination reduces acetals and ketals to the corresponding ethers but the yields are mixed.500 The full reduction of benz-aldehyde acetals to the toluene derivatives is realized by the initial reduction with Et3SiH/SnBr2-AcBr followed by Bu3SnH/AIBN (azobis(isobutyronitrile)) or LiAlH4.479 The overall yields are excellent. 

It is likely that the spectrum of compounds produced by all Mastophora species includes a wider range of compounds than those found in this study. Several Mastophora species catch male moths that are known to respond to pheromone compounds in the even-carbon number aldehyde/ acetate/alcohol chemical class, as well as males of other species that are known to respond to pheromone compounds in the odd-carbon number hydrocarbon chemical class (9, 13). 

The sex pheromones of moths generally are mixtures of two or more chemical components, typically aldehydes, acetates, alcohols, or hydrocarbons, produced in specialized glands by biosynthesis and modification of fatty acids (34). Often, a species-specific blend of components is the message, and males of many moth species, including M. sexta, give their characteristic, qualitatively and quantitatively optimal behavioral responses only when stimulated by the correct blend of sex-pheromone components and not by individual components or partial blends lacking key components (43, 44). 

A quite simple way to form the oxazolo[3,4- ]pyridine or thiazolo[3,4- ]pyridine ring system is to build the five-membered ring, respectively, starting from a 2-hydroxymethyl-piperidine or 2-thiomethyl-piperidine. The reaction of the latter compounds with aldehydes, acetals, phosgene, carbonates, or synthetic equivalents have been known for years and will therefore not be detailed here. Representative and typical examples are summarized in Table 10. 

At even higher temperature, the polysaccharides decompose further by extensive C-C bond breaking. This leads to the formation of C2 4 oxygenates such as glycol aldehyde, acetic acid and hydroxyacetone (CH3-CO-CH2OH). The formation of these products can be rationalized by a series of reactions that include,... 

The electrolysis of a-phenylthiocarboxy-lic acids (117) in MeOH containing LiCl04 gave the corresponding aldehyde acetals (118) (Eq. 16) [130],... 

Scheme 15 Conversion of alkyltosylamides into a-tosylamino aldehyde acetals.

Synonyms Acetic aldehyde Acetic ethanol Acetyl aldehyde Aldehyde AI3-31167 CCRIS 1396 EINECS 200-836-8 Ethanal Ethyl aldehyde FEMA No. 2003 NCI-C56326 NSC 7594 RCRA waste number UOOl UN 1089. 

Acetic Acid, Cupric Salt Acetic Acid, Dimethylamide Acetic Acid, Ethyl Ester Acetic Acid, Isobutyl Ester Acetic Acid, Isopropyl Ester Acetic Acid, Methyl Ester Acetic Acid, Nickel (II) Salt Acetic Acid, Propyl Ester Acetic Acid, Sec-Butyl Ester Acetic Acid, Zinc Salt Acetic Aldehyde Acetic Anhydride Acetic Ester Acetic Ether... 

Chabardes developed a process for the preparation of vitamin A and its intermediates, from cyclogeranylsulfone and Cio aldehyde-acetals [30]. For example, chlorocitral reacted with ethylene glycol, HC(OMe)3 and pyridinium tosylate to provide the chloroacetal (40%), as a mixture of two isomers. Reaction of this allylchloride with A-methylmorpholine oxide (NMO) and Nal furnished the aldehyde, as a mixture of four isomers. These compounds underwent condensation with P-cyclogeranylsulfone. Further chlorination of the sulfone-alkoxide salts, led to a mixture of sulfone-chloride acetals and their products of hydrolysis in 45-50% yield. Double elimination of the chloride and the sulfone, followed by hydrolysis with pyridinium tosylate (PPTS) gave retinal, as a mixture of all E and 13Z isomers (78/22). The overall yield from the chloroacetal was 18%. In another one-pot example, retinal was obtained in 52% yield from the aldehyde, and was then isomerised and reduced to retinol (all E 95.5, 13Z 4, 9Z 0.5) Fig. (8). 

Monoacetals of substituted succinaldehydes (162), readily prepared by hydroformylation of optically active a,(3-unsaturated aldehyde acetals, were used to synthesize 3-substituted thiophenes having an optically active substituent (163). In these cases, while the use of hydrogen sulfide and HC1 in methanol at room temperature was more convenient, comparison with formation of (163) by the Paal synthesis from an appropriately substituted succinic acid salt gave products having about the same amount of racemization (73JOC2361). 

B. a-Bromocinnamic aldehyde acetal. In a 250-ml. flask are placed 45 g. (0.21 mole) of a-bromocinnamic aldehyde, 50 ml. 

C. Phenylpropargyl aldehyde acetal. A solution of 20.7 g. (0.25 mole) of potassium hydroxide in 200 ml. of absolute ethanol is added to SO g. (0.18 mole) of o-bromocinnamic aldehyde acetal in a 500-ml. flask. The mixture is refluxed for 1.5 hours and poured into a 3-1. separatory funnel containing 1.5 1. of water. The oil which separates is extracted with three 170-ml. portions of chloroform, and the combined chloroform extracts are washed with three 75-ml. portions of water and then dried over 15 g. of anhydrous sodium sulfate. The chloroform is removed by distillation, and the residual oil is distilled from a modified Claisen flask. The yield of phenylpropargyl aldehyde acetal boiling at 153-156°/19 mm. is 28-31 g. (80-86%). 

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