Heptanal dimethyl acetal

Acetals derived from aliphatic aldehydes have odor characteristics that resemble those of the aldehydes but are less pronounced. These acetals contribute to the aroma of alcoholic beverages, but can rarely be used in flavoring compositions because they are not sufficiently stable. Since they are resistant to alkali, a number of them (e.g., heptanal dimethyl acetal and octanal dimethyl acetal) are occasionally incorporated into soap perfumes. 

Acetals of aldehydes are converted into esters by the action of ozone [111] or peroxy acids [277, 327], Butyraldehyde diethylacetal, when treated for 30 min with peroxy acetic acid and sulfuric acid as a catalyst, furnishes ethyl butyrate in a 69% yield after 11 h at 40 °C [277]. Enanthaldehyde (heptanal) dimethyl acetal reacts with ozone in dichloromethane at -78 °C for 15 h or at room temperature for 1.5 h to produce methyl heptanoate in 90% yield (equation 369) [111]. 

Aldehyde 14. SeeUndecanal Aldehyde Cl. See Formaldehyde Aldehyde C3. See Propionaldehyde Aldehyde C-5. See n-Valeraldehyde Aldehyde C-6. See Hexanal Aldehyde C-7. See Heptanal Aldehyde C-8. See n-Octanal Aldehyde C-9. See Nonanal Aldehyde CIO. See Decanal Aldehyde C-12. See Laurie aldehyde Methyl nonyl acetaldehyde Aldehyde C-13. See n-Tridecaldehyde Aldehyde C-14. See Myristaldehyde Aldehyde C14. Seey-Undecalactone Aldehyde C-16. See Ethyl methylphenylglycidate Aldehyde Cl 8. See y-Nonalactone Aldehyde C-7 dimethyl acetal. See Heptanal dimethyl acetal... 

Properties Flash pt. (CC) 75 C Toxicoiogy TSCA listed Uses Fragrance in cosmetics flavor Manuf./Distrib. Cooke Aromatics Ry. Ltd http //WWW.cookearomatics.com.au, Grau Arom ati cs http //www.grau-aromatics. de Heptanal dimethyl acetal CAS 10032-05-0 EINECS/ELINCS 233-103-6 FEMA 2541... 

Guaiacol Guaiacyl phenylacetate y-Heptalactone Heptanal dimethyl acetal 2-Heptanol... 

The first tenet of our working hypothesis, that different reagents induced different reaction pathways for acetals, could be tested spectroscopically if the putative reactive intermediates could be detected. Toward that end a simple substrate, heptanal dimethyl acetal, was combined with various... 

Figure 1. C-NMR Spectra of Heptanal Dimethyl Acetal and Lewis Acids at -80 C.

High performance liquid chromatography is used to determine the purity of calcitriol, and to separate it from related compounds. Using a 10 micron silica column of 25 cm length, and a mobile phase of spectroquality heptane ethyl acetate. methanol (50 50 1) at a flow rate of 1.7 ml/ minute, separation and quantitation are achieved. p-Dimethyl-aminobenzaldehyde may be used as an internal standard to compensate for variations in injection technique and instrumental conditions. With a 254 nm ultraviolet absorbance detector, 0.01 ug of calcitriol may be detected (3). 

The attempted transacetalization of the dimethyl acetal 135 a was partially successful only when it was boiled in excess ethanol in the presence of boron trifluoride etherate. The formation of the corresponding diethyl acetal 137 indicates that dialkyl acetals of dispiro [2.0.2. l]heptan-7-one can, in principle, enter reactions without ring opening and thus be applied as a synthetic equivalent of [3]triangulanone (Scheme 30) [125]. 

Dimethyl sulfoxide Ethanol Ethyl acetate Ethyl ather Ethyl formate Formic acid Heptane Isobutyl acetate Isopropyl acetate Methyl acetate... 

In general, bicyclic acetals are highly reactive toward acid-catalyzed hydrolysis. For example, the hydrolysis of 2,7-dioxabicyclo[2.2.1]heptane (2) in aqueous acetone containing dichloroacetic acid was 2.5 x 104 times faster than that of an acyclic reference compound, dimethyl acetal. [77] 2,6-Dioxabicyclo[Z2.1]heptane (79) is more reactive, and hydrolyzed 6.9 x 10s times faster than dimethyl acetal. [78] These rate accelerations for bicyclic acetals arise from a partial liberation of the ring strain on hydrolysis, and have been correlated to the reactivities of bicyclic acetals in the cationic ring-opening polymerization. [5]... 

Heptanal, which can be produced by hydroformylation of 1-hexene (Table 6.1, entry 2), has a strong fruity odor and is widely used as an ingredient in the aroma industry. In dilution, it develops a sweet, fruity, nutty, fatty-cognac-like scent. Also its dimethyl acetal is employed, which confers the product a green, herbaceous, and somewhat nutty odor. It is occasionally added to soap perfumes. Aldol condensation with benzaldehyde gives a-hexyl cinnamaldehyde its odor is described as sweet and floral and reminiscent of jasmine. It is widely used in domestic fragrances [19]. 

Sulfur compounds dimethyl sulfoxide (DMSO) dimethylthioformamide (DMTF) hexamethylthiophosphoric triamide iV-methyl-2-ihiopyiTolidinone (NMTP) sulfolane or tetramethylene sulfone (TMS) sulfur dioxide 2,2 -thiodiethanol. Others benzene y-butyrolactone (y-BL) chlorobenzene 1,2-dichloroethane (DCE) dichloromethane (DCM) dimethyl carbonate ethyl acetate ethylene carbonate (EC) heptane methyl acetate (MA) 3-methyl-2-oxazolidone nitrobenzene (NB) nitromethane (NM) propylene carbonate (PC) toluene xylene. 

Hydrolase-catalyzed acylation can be used to purify a diastereo- and enantiomerically enriched product. For example dimethylzinc addition to the racemic aldehyde 77 furnishes the racemic phenylsulfanylbutanol 78 (Scheme 4.29) in a 95/5 (2R, 3R )/(2R, 3S )-mtio. When this is treated with Chirazyme L2 (CALB) and vinyl acetate in heptane it is resolved with a high E-value (>400) [91]. However the diastereomeric ratio in the remaining substrate and produced ester is virtually unchanged. To circumvent the problematic contamination with the undesired diastereomers, enantiomerically enriched aldehyde 77 was reacted with dimethyl-zinc to furnish one major stereoisomer of 78 contaminated with a small amount of a mixture of the other three (Scheme 4.29). Because the two major contaminants had the opposite configuration at position 2 relative to the major product, these contaminants were efficiently removed from the major product and the trace byproduct by treatment with the 2R-selective Chirazyme L2 (CALB) and vinyl acetate in heptane to furnish virtually diastereo- and enantiomerically pure acetate (2R,3R)-79 or the alcohol (2S,3S)-78 (Scheme 4.29) [91]. 

Methyl derivatives were used by Martin and Driscoll [509] they were prepared by treatment with dimethyl sulphate and applied to the analysis of barbiturates in serum, as follows. A 2-ml volume of a saturated solution of sodium dihydrophosphate and 10 ml of diethyl ether were introduced into a test-tube containing 2 ml of serum. The test-tube was closed and shaken vigorously for 30 sec, centrifuged for 1 min, then 7 ml of the extract were transferred into another test-tube and the ether was removed in a stream of air in a water-bath. The residue was dissolved in 2 ml of methanol with 10% of water (v/v), saturated with potassium carbonate, and 0.1 ml of dimethyl sulphate were added and the mixture was heated in a water-bath at 60°C for 4 min. At this temperature methanol was removed in a stream of air (3 min) and the residue was extracted into 1.5 ml of -heptane with the addition of 1 ml of 1 M acetate buffer (pH 6). A 1 -ml volume of the n-heptane extract was transferred into a small test-tube, evaporated carefully in order that losses of the derivatives might be avoided, and dissolved in 100 (A of acetone (containing an internal standard if necessary) 5 jul were analysed on a column packed with 5% of SE-30 at 175°C. 

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