Dihydroisopimaric acids

Figure 12.12 THM GC/MS curves of a Winsor Newton lemon alkyd paint (a) and of an alkyd sample taken from Fontana s work Concetto spaziale (1961) (b). Peak assignments 1, 1,3 dimethoxy 2 propanol 2, 1,2,3 trimethoxy propane 3, 3 methoxy 1,2 propandiol 4, 4 chloro benzenamine 5, 3 methoxy 2,2 bis(methoxymethyl) 1 propanol 6, 3 chloro N methyl benzenamine 7, 3 methoxy 2 methoxymethyl 1 propanol 8, 4 chloro N methyl benzenamine 9, phthalic anhydride 10, 3 chloro 4 methoxy benzenamine 11, suberic acid dimethyl ester 12, dimethyl phthalate 13, azelaic acid dimethyl ester 14, sebacic acid dimethyl ester 15, palmitic acid methyl ester 16, oleic acid methyl ester 17, stearic acid methyl ester 18, 12 hydroxy stearic acid methyl ester 19, 12 methoxy stearic acid methyl ester 20, styrene 21, 2 (2 methoxyethoxy) ethanol 22, 1,1 oxybis(2 methoxy ethane) 23, benzoic acid methyl ester 24, adipic acid dimethyl ester 25, hexadecenoic acid methyl ester 26, dihydroisopimaric acid methyl ester 27, dehydroabietic acid methyl ester 28, 4 epidehydroabietol...

The X-ray analysis of the y-lactone (79) formed by acid treatment of dihydroisopimaric acid has shown that it possesses a trans a/b ring junction, in contrast to some previous structural assignments. The solvolysis of virescenol B... 

Pimaric acid (6) and isopimaric acid (7) differ in carbon skeleton from abietic acid, and the amounts initially present in rosin are lost in the process described for the preparation of dehydroabietic acid. In the step of dehydrogenation with palladium the two acids act as hydrogen acceptors and are converted into a mixture of dihydro-pimaric and dihydroisopimaric acids. Note that pimaric acid and isopimaric acid have been shown to be rearranged to abietic acid by concentrated sulfuric acid. 

Fatty acid esters Ethyl acetate, methyl methacrylate, trimethylolpropane trimethacrylate, decyl methacrylate, 2-hydroxyethyl methacrylate, ethoxy ethyl acetate, methyl palmitate, ethyl palmitate, isopropyl palmitate, butyl palmitate, isobutyl palmitate, methyl margarate, butyl margarate, methyl stearate, ethyl stearate, butyl stearate, isobutyl stearate, methyl oleate, bis(2-ethylhexyl) adipate, bis(2-ethylhexyl) sebacate, methyl linoleate, methyl laurate, octyl laurate, methyl myristate, isobutyl myristate, butyl myristate, dihydroisopimaric add methyl ester... 

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