Acetaldehyde Diethyl Acetal

A -(2 2-Diethoxyethyl)anilines are potential precursors of 2,3-unsubstituted indoles. A fair yield of 1-methylindole was obtained by cyclization of N-inethyl-M-(2,2-diethoxyethyl)aniline with BFj, but the procedure failed for indole itself[2], Nordlander and co-workers alkylated anilines with bromo-acetaldehyde diethyl acetal and then converted the products to N-trifliioro-acetyl derivatives[3]. These could be cyclized to l-(trifluoroacetyl)indoles in a mixture of trifluoroacetic acid and trifluoroacetic anhydride. Sundberg and... 

Anesthesia. Materials that have unquestionable anesthetic properties are chloral hydrate [302-17-0] paraldehyde, dimethoxymethane [109-87-5] and acetaldehyde diethyl acetal. In iadustrial exposures, however, any action as an anesthesia is overshadowed by effects as a primary irritant, which prevent voluntary inhalation of any significant quantities. The small quantities which can be tolerated by inhalation are usually metabolized so rapidly that no anesthetic symptoms occur. 

Numerous variations of this reaction have been studied, principally those involving a prior inclusion of the nuclear sulfur atom in a thioacylamino compound. Thus, thiobenz-amido acetaldehyde diethyl acetal (8) underwent ring closure to 2-phenylthiazole (9) on gentle heating (57JCS1556). Similarly, iV-thioacyl a-amino acids also undergo ready ring closure to thiazoles. 

Acetaldehyde ammonia, al62 Acetaldehyde diethyl acetal, d303 Acetaldehyde dimethyl acetal, d504... 

Thus, in a novel synthesis of hypoglycine A (96), hydroxycyclopropanation of ethenyl-acetaldehyde diethyl acetal (93) followed by formal dehydration of the cyclopropanol 94 via its tosylate intermediate gave the methylenecyclopropane species 95, a key precursor to the target amino acid (Scheme 11.26) [92]. 

When L-gulono-1,4-lactone was treated with acetaldehyde diethyl acetal in N,N-dimethylformamide-benzene in the presence of a catalytic amount of p-toluenesulfonic acid, 5,6-O-ethylidene-L-gulono-1,4-lactone (54) was formed86 in 61% yield (40%, recrystallized). It is interesting that compound 54 was clearly a mixture of diastereo-... 

In contrast to the other large cats, the urine of the cheetah, A. jubatus, is practically odorless to the human nose. An analysis of the organic material from cheetah urine showed that diglycerides, triglycerides, and free sterols are possibly present in the urine and that it contains some of the C2-C8 fatty acids [95], while aldehydes and ketones that are prominent in tiger and leopard urine [96] are absent from cheetah urine. A recent study [97] of the chemical composition of the urine of cheetah in their natural habitat and in captivity has shown that volatile hydrocarbons, aldehydes, saturated and unsaturated cyclic and acyclic ketones, carboxylic acids and short-chain ethers are compound classes represented in minute quantities by more than one member in the urine of this animal. Traces of 2-acetylfuran, acetaldehyde diethyl acetal, ethyl acetate, dimethyl sulfone, formanilide, and larger quantities of urea and elemental sulfur were also present in the urine of this animal. Sulfur was found in all the urine samples collected from male cheetah in captivity in South Africa and from wild cheetah in Namibia. Only one organosulfur compound, dimethyl disulfide, is present in the urine at such a low concentration that it is not detectable by humans [97]. 

Kuethe et al. reported the synthesis of the tjipanazoles D (359), I (360), B (369), and E (370) starting from the nitro derivative 1496 (796). This route involves the synthesis of 2,2 -bisindoles, followed by a two-carbon insertion through condensation with (dimethylamino)acetaldehyde diethyl acetal to afford the indolocarbazole ring. 

Reaction of the TMS-nitro compound 1496 and the indole carboxaldehyde 1497 with a catalytic amount of TBAF led to the desired alcohol 1498, which, on further treatment with TFAA, followed by elimination of the corresponding trifluoroacetate with DBU, afforded the frans-stilbene 1499. Reductive cyclization of 1499 under Cadogan-Sundberg conditions afforded the bisindole 1500. Finally, condensation of 1500 with (dimethylamino)acetaldehyde diethyl acetal led to tjipanazole D (359) in 71% yield (796) (Scheme 5.255). 

Aldehydes and Other Low-Boiling Components. As mentioned, a low-boiling fraction, called heads, is normally taken from the vent condenser during the distillation of wine into brandy. The principal impurities removed are acetaldehyde, diethyl acetal, ethyl acetate, and acetalde-hyde-sulfurous acid. 

Stannic chloride has been used successfully to cyclize a few (arylthio)acetaldehyde diethyl acetals.291... 

Acetaldehyde ammonia, al63 Acetaldehyde diethyl acetal, d251 Acetaldehyde dimethyl acetal, d438 Acetamidoacetic acid, a46 2-Acetamidopentanedioic acid, a45... 

To a solution of potassium t-butoxide (0.11 mol) in 100 ml DMF was added thiobenzoic acid (0.11 mol) and the solution partially evaporated in vacuo, benzene added in two consecutive portions and evaporated in vacuo each time. To the residual DMF solution was added bromoacetaldehyde diethyl acetal (0.1 mol) and the mixture stirred at 120°C for 15 h. After cooling, it was poured onto water (500 ml), the product extracted with ether, the extract washed with aqueous NaHC03 followed by water, then dried and the solvent removed in vacuo. The residue was distilled in vacuo to give 17.2 g of pure 2-thiobenzoyl acetaldehyde diethyl acetal, boiling point 131-133°C/0.07 mm. 

The 2-thiobenzoyl acetaldehyde diethyl acetal (17.2 g) was dissolved in 100 ml THF followed by the addition of 6 g NaOH in 20 ml H20. The mixture was refluxed under N2 for 15 h, then cooled and diluted with water (200 ml) and the product extracted with ether (3 x 200 ml). The extract was dried, the solvent removed in vacuo and the residue distilled to yield 7.1 g of mercaptoacetaldehyde diethylacetal. 

While aliphatic aldehydes fail to react cleanly, the reaction of 21 with benzaldehyde in the presence of 1 equiv of TBSOTf gives the TBS-sub-stituted aldol adduct 49 as a 1 1 ratio of diastereomers. In addition to aldehydes and ketones, electrophilic additions can also be achieved with acetals (Figure 11). The reaction of 21 with acetaldehyde diethyl acetal promoted by TBSOTf gives 3//-pyrrolium complex 50 as a 1 1 ratio of diastereomers, a reaction that circumvents the poor results obtained with aliphatic aldehydes. 

Acetaldehyde Diethyl Acetal FEMA No. 2002 Acetal 118.17/C6Hi402/ 0-C2H5 H3C-HC. o-c2h5 colorless to pale yel liq/ ethereal, fruity s—prop glycol, veg oils ss—water/ 102° 1 mL in 1 mL 95% ethanol... 

Acetaldehyde Diethyl Acetal 642 Benzyl Formate 660 Chamomile Oil, German Type... 

Acetaldehyde Diethyl Acetal View Flavor Chemical... 

Acetaldehyde Diethyl Acetal 2-Acetyl Thiazole Allyl Phenoxy Acetate Allyl Propionate Borneol... 

Acetaldehyde Diethyl Acetal, 64 Acetoin, 64 2-Acetylpyrrole, 64 2-Acetyl Thiazole, 64 Allyl Isothiocyanate, 64 Allyl Phenoxy Acetate, 64 Allyl Propionate, 66... 

Indigo Carmine, 24 Indigotine, 24 Infrared Spectra, 93 Acetaldehyde Diethyl Acetal, 94... 

The synthesis and chemistry of an 7] -selenophene osmium complex 50 has been studied <19990M1559>. Protonation and electrophilic substitution with acetaldehyde diethyl acetal occurred at C-2. Methylation of complex 50 with methyl triflate gave 51 which upon treatment with tetrabutylammonium borohydride (TBAB) led to the selenophene ring-opened complex 52 (Scheme 5). 

Acetaldehyde diethyl acetal (1,1-diethoxyethane) Ethylene glycol dimethyl ether (glyme)... 

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