Methyl dehydroabietate

Figure 8.4 Total ion current chromatograms of the (a) acidic and (b)neutral fractions of a sample collected from an amphora recovered in Fayum. DDA, didehydroabietic acid DA, dehydroabietic acid 70DA, 7 oxo dehydroabietic acid 70A, 7 oxo abietic acid 15Hy70DA, 15 hydroxy 7 oxo dehydroabietic acid 5HyDA, 15 hydroxy dehydroabietic acid R, retene MDA, methyl dehydroabietate. Slf internal standard, hexadecane IS2, internal standard, tridecanoic acid...

Figure 7.1 Total ion current (TIC) chromatogram obtained by GC-MS analysis of a resin (Pinus sylvestris). The diterpenoid resin acids were methylated (using diazomethane) to improve chromatographic performance. Peak identities 1, Methyl pimarate 2, Methyl sandaracopimarate 3, Methyl isopimarate 4, Methyl palustrate 5, Methyl dehydroabietate 6, Methyl abietate 7, Methyl neoabietate. For GC-MS operating conditions, see Heron and Pollard (1988).

Metal hydride reduction of methyl dehydroabietate (64b) afforded alcohol (65) whose tosyl derivative on heating with sodium iodide and zinc in dimethylformamide yielded (66). The use of hexamethylphosphoramide gave an inferior yield of (66). Regio and stereoselective acetoxylation with Pb(OAc)4 in acetic acid at 100°C gave only 30% yield of (67) but the same experiment realized with Pb(OAc)4 using a Hg medium-pressure lamp at room temperature yielded (67) in 74%. The H NMR spectrum of (67) showed that the OAc group was introduced in 7a-position. This on subjection to acid-catalyzed 13-elimination (EtOH/10% HC1) produced (68) in quantitative yield. 

Dehydroabietie acid. Methyl dehydroabietate (2) can be prepared conveniently and in 85% yield by dehydrogenation of methyl levopimarate (1) with diethyl azodi-carboxylate in refluxing benzene.3... 

Methyl-5-decene-3-yne-l-ol, 909 Methyl dehydroabietate, 603, 925 Methyl 2-desoxy-2-iodo- -D-glucopyrano-... 

Methyl desoxypodocarpate (1), which has a highly hindered axial methyl ester group, reacts with Li-NHa to give the corresponding acid in about 75% yield and the expected alcohol is only a minor product. Methyl dehydroabietate (3), in... 

Hydrolysis of hindered esters. Chang and Wood found that potassium f-butoxide in dimethyl sulfoxide effectively cleaves hindered esters under conditions adjusted according to the degree of hindrance. Thus methyl dehydroabietate (1), in which the... 

Baleizao C, Pires N, Gigante B et al (2004) Friedel-Crafts reactions in ionic liquids the counter-ion effect on the dealkylation and acylation of methyl dehydroabietate. Tetrahedron Lett 45 4375-4377... 

Within the GC detectable range, we identified the different composition of the liquid products from the various origins by using a GC-MS analysis. The liquid products from Kraft pine lignin contain mainly guaiacol and methyl dehydroabietate. The liquid products from oat hull, hardwood, and switchgrass contain acetic acid, 1-hydroxy-2-propanone, and/ or furfural, which are the products of hemicellulose and cellulose. This further confirms that these three materials contain hemicellulose and cellulose. The liquid products have only two to three component differences from one biomass species to another. But the composition distributions are quite different among species (Table 4). So the composition of liquid products depends on the type of raw materials. 

Dehydroabietic acid, methyl ester. See Methyl dehydroabietate Dehydroabietylamine CAS 1446-61-3 EINECS/ELINCS 215-899-7 Synonyms 1,4A-Dimethyl-7-isopropyl-1,2,3,4,4A,9,10,1 OA-octahydro-1-phenanthrene methylamine... 

Podocarpa-7,13-dien-15-oic acid, 13-isopropyl-, methyl ester. See Methyl abietate Podocarpa-8,11,13-trien-15-oic acid, 13-isopropyl-, methyl ester. See Methyl dehydroabietate... 

Methoxy PEG-22/dodecyl glycol copolymer N-Methylacetamide Methylcellulose Methyl dehydroabietate Methyl dihydroabietate Methyl hydroxyethylcellulose Methylstyrene/vinyltoluene copolymer ... 

The reduction of methyl dehydroabietate at high teirperature leads to the formation of dehydroabietanol (Fig. 4.16), whose light colour and high stability make it a useful intermediate for the synthesis of a variety of esters used in protective coatings, adhesives and plasticizers [5]. 

Figure 4.22 Synthesis of secondary amines of methyl dehydroabietate.

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