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Acetals compounds

Section 25 13 Glycosides are acetals compounds m which the anomenc hydroxyl group has been replaced by an alkoxy group Glycosides are easily prepared by allowing a carbohydrate and an alcohol to stand m the presence of an acid catalyst... [Pg.1062]

The early 1990s have also seen much interest in biodegradable cellulose acetate compounds. [Pg.616]

A wide range of cellulose acetate compounds are commercially available. The properties of these compounds depend on three major factors ... [Pg.625]

Typical values for the principal properties of cellulose acetate compounds are tabulated in Table 22.2 in comparison with other cellulosic plastics. Since cellulose acetate is seldom used today in applications where detailed knowledge of physical properties are required these are given without further comment. [Pg.626]

As a result of development work between the Battelle Institute in Frankfurt and a German candle-making company, Aetema, biodegradable cellulose acetate compounds have been available since 1991 from the Rhone-Poulenc subsidiary Tubize Plastics. They are marketed under the trade names Bioceta and Biocellat. The system is centred round the use of an additive which acts both as a plasticiser and a biodegrading agent, causing the cellulose ester to decompose within 6-24 months. [Pg.627]

In 1991 Rhone-Poulenc offered biodegradable cellulose acetate compounds in which an additive acts both as plasticiser and biodegrading agent (see Section 22.2.2.1). [Pg.882]

Another striking difference relates to the diterpenes (Figure 16.3) B. carterii reveals strong peaks that have been assigned to verticilla-4 (20),7,ll-triene (compound 1), incensole acetate (compound 2), and incensole (compound 3) and, on the other hand, Boswellia serrata shows peaks of m- and / -camphorene (compoimd 4 and compound 5) as well of cembrenol (= serratol) (compound 6). [Pg.393]

The brownish colored zone (Rj 0.28) of incensole (compound 3), which occurs in both the resin and the volatile fractions of B. carterii, draws the hue between the volatile diterpenes and the nonvolatile triterpenes. B. carterii reveals two further colored prominent spots, a yellowish-ochre (Rf 0.65) of incensole acetate (compound 2) and a violet-colored spot (Rj 0.98) of verticilla-4(20),7,ll-triene (compound 1). Lane 2 and lane 3 reveal a light blue area (Rj 0.60) of 1,8-cineol that is only visible in freshly distilled oils. [Pg.395]

FIGURE 16.6 Purification steps of fraction 2 and 3 from B. carterii. (A) GC and TLC data of fractions 2 and 3. (B) GC data of incensole acetate after separation and purification of the zone Rf 0.50. (C) Mass spectrum of incensole acetate (compound 2). [Pg.399]

FIGURE 16.9 An overview of the marker substances of (A) B. carterii and (B) B. serrata. (A) Lane 1 incensole (compound 3), lane 2 and 3 hexane extract of B. carterii, lane 4 incensole acetate (compound 2), lane 5 verticilla-4(20),7,ll-triene (compound 1). (B) Lane 1 m-camphorene (compound 4) and p-camphorene (compound 5), lane 2 cembrenol (compound 6), lane 3 Hexane extract of B. serrata. [Pg.403]

In 1979 the bieyclic diol exo-2,ejco-6-dihydroxy-2,6-dimethylbicyclo[3.3.1]nonane (i) was prepared and observed to co-crystallise with various solvents, including ethyl acetate, chloroform, toluene, dioxane, and acetone. A crystal structure determination of the ethyl acetate compound revealed the occurrence of a helical canal host structure, containing ethyl acetate as guest (with 3 1 diol ethyl acetate stoichiometry), and that spontaneous resolution had occurred on crystallisation of the multimolecular inclusion compound 6>. [Pg.150]

Partly saturated pyrazino[l,2-r-]pyrimidines were prepared by formation of the pyrazine ring. 2-Substituted-8-hydroxy-3,4-dihydro-177,277-pyrazino[l,2-r-]pyrimidin-l-ones were prepared by a [6+0] synthesis involving cyclization of 6-hydroxy-pyrimidine-4-(fV-hydroxyethyl)carboxamides <2005W02005/087766>. The 2/7-pyra-zino[l,2-c]pyrimidine-3-carboxamide 164 (Y = NH) was formed from [5+1] atom fragments via the uracil derivative 163 (Y = NH) and DMF-dimethyl acetal. Compounds 163 were prepared from 6-chloromethyluracil and glycine methyl ester 162 (Y = NH) (Scheme 20) <2004W02004/014354>. [Pg.280]

The benzotriazolyl derivative of acrolein acetal, compound 882, is lithiated, treated with chlorodiphenylphosphine, and the obtained intermediate is oxidized with hydrogen peroxide to phosphine oxide 883 (Scheme 145). The relatively acidic proton in derivative 883 is easily removed by a base, and the obtained anion adds to a carbonyl group of aldehyde or ketone. Subsequent rearrangement and elimination of the phosphorane group generates diene 884. For the derivatives of aldehydes (884, R2 = H), (E)-(E) stereoselectivity of the elimination is observed. Acidic alcoholysis of dienes 884 affords esters of P,y-unsaturated carboxylic acids 885 < 1997JOC4131>. [Pg.100]

Acetyl iodide is very reactive and it reacts efficiently with water or methanol leading to acetate compounds. Hydrolysis of acetyl iodide along with the subsequent conversion of methanol to methyl iodide are very rapid under the reaction conditions leading to a complete mechanistic cycle. [Pg.74]

Harayama Y, Yoshida M, Kamimura D, Wada Y, Kita Y (2006) The Efficient Direct Synthesis of N.O-Acetal Compounds as Key Intermediates of Discorhabdin A Oxidative Fragmentation Reaction of a-Amino Acids or P-Amino Alcohols by Using Hypervalent Iodine(III) Reagents. Chem Eur J 12 4893... [Pg.445]

The introduction of the 5a-bromine (compound 424) into 5cr-cholestan-6-on-3-yl acetate (compound 176) introduces a y-gauche interaction at carbons 1, 3, 7, and 9 of —6-1, -2-8, -6-3, and -6-7 ppm respectively. Presumably the effect at C-3 is partially compensated... [Pg.212]

The product obtained (formula B in Figure 9.12) is, in the broadest sense of the word, an acetal. This is a collective term for compounds of the structure R R2C(Nu)2, where Nu can be OR3 (so-called 0,0-acetal), SR3 (so-called S,S-acetal), or NR3R4 (so-called N,IV-acetal). O, O- and S S-acetals are isolable compounds. AjIV-acetals can in general only be isolated when they are cyclic or substituted on both N atoms by an electron acceptor. There are also mixed acetals, compounds R R2C(Nu)2 with two different substituents Nu, such as R R2(OR3)(OR4) (so-called mixed QO-acetal) or R R2(OR)(SR) (so-called QS-acetal). [Pg.372]

Figure 3. Rate of Heating vs Glass Transition Temperature for Poly (vinyl acetate) Compound. Figure 3. Rate of Heating vs Glass Transition Temperature for Poly (vinyl acetate) Compound.

See other pages where Acetals compounds is mentioned: [Pg.10]    [Pg.627]    [Pg.363]    [Pg.391]    [Pg.396]    [Pg.401]    [Pg.401]    [Pg.397]    [Pg.365]    [Pg.54]    [Pg.255]    [Pg.448]    [Pg.345]    [Pg.145]    [Pg.14]    [Pg.1028]    [Pg.186]    [Pg.196]    [Pg.14]    [Pg.837]    [Pg.5]    [Pg.264]    [Pg.363]    [Pg.308]    [Pg.88]    [Pg.94]    [Pg.405]    [Pg.14]    [Pg.137]   
See also in sourсe #XX -- [ Pg.88 ]

See also in sourсe #XX -- [ Pg.88 ]

See also in sourсe #XX -- [ Pg.162 ]

See also in sourсe #XX -- [ Pg.88 ]




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