Hydrate, Acetic

The bicyclic monoterpenes cis-sabinene hydrate and cit-sabinene hydrate acetate are known as the major and original flavor compounds of marjoram Origanum majorand) Relatively large quantities of cis- and trans-sabinene hydrate were detected in the genus Origanum m-Sabinene hydrate acetate was found in relatively large amounts in solvent and CO2 extracts of O. and as a minor component in hydro-... 

Novak J, Bitsch C, Pank F, Langbehn J, Franz CM, Distribution of the cis-sabinene hydrate acetate-chemotype in accessions of marjoram Origanum majorana L.), Euphytica 127 69-74, 2002. 

The anhydrous acetates of the rare earths have recently been prepared. Moeller et al. [355] obtained them for La, Dy, Ho, Er, Yb and Y by the azeotropic distillation of a mixture of hydrated acetates with N,N -dimethylformamide (DMF) and benzene. In the case of Ce, Pr, Nd, Sm, Eu and Gd the same method gave a monosolvated acetate, M(C2Hs02)3 DMF. However, the anhydrous acetates of Ce, Pr, Nd, Sm, Eu and Gd can be prepared [355] by vacuum desolvation of the monosolvated compounds. A direct desolvation of the acetates in vacuum at —150° C was attempted by Witt and Onstott [389] after dissolution of the rare earth oxides in 50 per cent acetic acid, and anhydrous acetates of definite composition were obtained for La, Eu, Gd, Tb, Dy, Ho, Er, Tm, Lu and Y. 

Recently Mint and Kecki [103] examined the Raman spectra of solutions of nitric acid in anhydrous and hydrated acetic acid. They have shown that at a concentration of 2 moles HN03 per litre of CH3COOH, i.e. for the solution containing 12.6% HN03 in acetic acid, the 1304 cm 1 line, probably corresponding to the nitronium ion, N02+, can be seen. The intensity of the line increases with concentration of nitric acid. Thus we can say that the acetic acid facilitates the formation of the nitronium ion. 

Some hydration compounds of acetic acid have been reported by various experimental methods. The density measurements for acetic acid and water systems by Kipling [1] reveal the presence of mono-hydrated monomers. Ng and Shurvell [2,3] reported the species of hydrated acetic acid monomers and dimers... 

Q Name ketones and aldehydes, and draw the structures from their names. Identify their hydrates, acetals, imines, and other derivatives. Problems 18-37, 38, 40,41, and 61... 

Carboxylate complexes of the lanthanides differ from those of many trivalent transition metals in that they do not adopt oxo-centered structures with M3 O cores. The hydrated acetates have a long history, with the first examples reported by Cleve in 1874 they can be synthesized by dissolving the oxides in acetic acid and the anhydrous compounds obtained by azeotropic distillation. 

A survey of the temperatures of dehydrations and decompositions of thirteen hydrated acetates has been given by Baraldi [43] who used spectroscopic methods to identify intermediates and products. 

Composition Main constituents are a- and y-terpinene, terpinene-4-ol, a-terpineol, linalool, linalyl acetate and cis-sabinene hydrate. The latter, along with its transisomer and terpinene-4-ol, is considered as typical aroma carrier of sweet marjoram. The quantitative composition, especially of oils of uncertain botanical origin, varies considerably ]155]. Oils from India contain eugenol, methyl chavicol and geraniol in marked amounts ]156], while these compounds are negligible or absent in European oils. Commercial oils from Turkey contain considerable amounts of carvacrol, some up to 80% [157]. Also the production process can influence the oil composition, e.g. cis-sabinene hydrate is partly converted to terpinene -ol during steam distillation. The genuine plant additionally contains cis-sabinene hydrate acetate, which is almost totally hydrolysed in the steam-distilled oil [158]. 

It appears that the methyl radical is more stable in crystals with the more open structure characteristic of two- or three-dimensional hydrogen-bonded networks. The structure of zinc acetate dihydrate, for example, is known (37), and the acetate ions are tied together by hydrogen bonds in two-dimensional sheets with only weak Van der Waals forces between layers. Since the formation of CH3 in hydrated acetates presumably is the result of dissociation of a precursor of the type CH3C002", which... 

Hydrated acetate, F JJ3, saralasin acetate, Sarenin. Described as C42HwNt Ow.xCjH4Oi.xHjO. Fluffy white powder. mp 256. Sol in water, 5% aq dextrose. 90-95% aq alcohol. LDgo i.v. in male mice 1171 mg/kg (Huang). 

Synonyms.—Acetic Hydrate Hydrated Acetic Acid. 

Variability of chemotypes continues also within the marjoramy O. majorana. Novak et al. (2002) detected in cultivated marjoram accessions additionally to c -sabinene hydrate the occurrence of polymorphism of cw-sabinene hydrate acetate. Since this chemotype did not in uence the sensorial impression much, this chemotype was not eliminated in breeding, while an ojf-flavor chemotype would have been certainly eliminated in its cultivation history. In natural populations of O. majorana from Cyprus besides the classical CM-sabinene hydrate type, a chemotype with a-terpineol as main compound was also detected (Novak et al., 2008). The two extreme ojf-flavor chemotypes in 0. majorana, carvacrol and a-terpineol chemotypes, are not to be found anywhere in cultivated marjoram, demonstrating one of the advantages of cultivation in delivering homogeneous qualities. 

Concentration changes of acetic acid were measured by titration with a standard sodium hydroxide solution. Extents of adsorption of acetic acid on 850 °C PVDC carbons (0,41 and 70 wt% bum-off) are plotted against acetic acid concentration in Figure 8.3. Extents of adsorption of acetic acid by the carbons reached a maximum in about 4M acetic acid (mole fraction = 0.09). The maximum amounts of acetic acid plotted in these isotherms (Figure 8.3) correspond more to capillary condensation than pore filling mechanisms (Table 8.1) with the possibility of capillary condensation of hydrated acetic acid molecules. Thus, no unequivocal conclusions are possible. The conclusions of this study, relevant to understanding adsorptions from solution are as follows ... 

Adsorption of acetic acid from aqueous solution most probably involves competition with the water molecules. Hence, it is difficult to distinguish between adsorption restricted to the microporosity (micropore pore filling), from the adsorption of hydrated acetic acid molecules (capillary condensation). 

C7H28CI3C0N10S3, trans-Dichlorobis(ethylenediamine)cobalt III) chloride - tris(thiourea), 39B, 440 C8H6K3M0N6O3S6 r Potassium hexaisothiocyanatomolybdate(lII) hydrate-acetic acid, 33B, 422... 

A mixture of phenylalanine, o-acetylbenzoic acid, acetic acid, and toluene refluxed 48 hrs., while the aq. condensate passes through a Dean-Stark trap -> N-protected phenylalanine (Y 82%) added to a mixture of 85%-hydrazine hydrate, acetic acid, and water, then refluxed 5 hrs. phenylalanine (Y 80%). F. e. s. C. A. Panetta and A. L. Miller, Synthesis 1977, 43. 

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