5708-85-0

Upstream product

• 471-77-2 neoabietic acid 
• 75-00-3 chloroethane 
• 10028-15-6 ozone 
• 20085-81-8 13-Oxopodocarp-8⁽¹⁴⁾-en-18-saeure-methylester 
• 19402-34-7 methyl abieta-8,13⁽¹⁵⁾-dien-18-oate 
• 105405-29-6 methyl 13-oxo-podocarp-8-en-18-oate 
• 388120-50-1 C₂₁H₃₂O₃ 
• 80037-90-7 1,1,3,3-tetramethyl-2,3-dihydro-1H-isoindol-2-yloxoyl radical 
• 113903-96-1 7-(1-hydroperoxy-1-methyl-ethyl)-1,4a-dimethyl-1,2,3,4,4a,4b,5,6,10,10a-decahydro-phenanthrene-1-carboxylic acid 
• 5749-13-3 rac-13-methoxy-podocarpa-8,11,13-trien-16-oic acid 
• 25914-43-6 2-hydroxy-2-(3-methoxy-phenethyl)-1,3-dimethyl-cyclohexanecarboxylic acid ethyl ester 
• 25914-39-0 2-hydroxy-2-(3-methoxy-phenylethynyl)-1,3-dimethyl-cyclohexanecarboxylic acid ethyl ester 

Downstream Products

• 101821-23-2 15-hydroxyabietic acid 
• 113903-96-1 7-(1-hydroperoxy-1-methyl-ethyl)-1,4a-dimethyl-1,2,3,4,4a,4b,5,6,10,10a-decahydro-phenanthrene-1-carboxylic acid 

Relevant academic research and scientific papers

Conversion of a cyclic α,β-unsaturated ketone into a tertiary dienyl hydroperoxide: Application to the first hemisynthesis of 15-hydroperoxyabietic acid

The first hemisynthesis of 15-hydroperoxyabietic acid, a major contact allergen among the oxidation products of colophony, is reported. The key step includes a new approach to easily obtain a dienyl tertiary hydroperoxide from a cyclic α,β-unsaturated ketone. The procedure is based on the formation of a bromodiene using a Vilsmeier's reagent, followed by a halogen/metal exchange and alkylation with acetone, to afford the dienyl alcohol precursor of the hydroperoxide.

Identification of radical species derived from allergenic 15-hydroperoxyabietic acid and insights into the behaviour of cyclic tertiary allylic hydroperoxides in Fe(II)/Fe(III) systems

To understand the skin sensitization mechanism of 15-hydroperoxyabietic acid, the major allergen in colophony, we first examined the formation of potential reactive radicals derived from its reaction with light, heat and TPP-Fe3+. Trapping with 1,1,3,3-tetramethylisoindolin-2-yloxyl nitroxide confirmed the?formation of carbon-centred radicals derived from allyloxyl/allylperoxyl radicals as a consequence of the hydroperoxide scission. Particular interest was further given to the reactivity with Fe(II)/Fe(III) due to?the biological importance of haem containing enzymes. Using a monocyclic 15-hydroperoxyabietic acid-like compound as a model of allergenic allylic hydroperoxides, we evidenced, by the ESR spin-trapping technique, the competition between carbon and oxygen-centred radicals formed in the presence of Fe(II)/Fe(III) in organic/aqueous media. We complemented the study by showing the possibility of formation, via a radical mechanism induced by ferric chloride, of an adduct between the allylic hydroperoxide and N-acetyl-cysteine ethyl ester. The results gave new knowledge on the possible generation of highly reactive radicals that could lead to the formation of antigenic structures.

Investigation of the Allergenic Principles from Colophony: Autoxidation, Synthesis, and Sensitization

The autoxidation of abietic acid (1a), levopimaric acid (2a), and dehydroabietic acid (3a) was studied and the compounds 3a as well as (after esterification) 8b, 9b, 10b, 11b (from 1a); 6b (from 2a); and 4b, 5b (from 3a) were isolated for the first time.Some derivatives (6a, 6b, 13b/14b, and 7b) were semi-synthezised.The isolated autoxidation products, the synthetic compounds and some polar fractions of natural colophony were tested for their sensitizing capacity.Compounds 4a, 10b, 16, and 18 as well as the combined polar fraction A-D of colophony show enhanced sensitizing capacity.Methylation of the acids to the ester significantly reduces their activity.Key Words: Resin acids, autoxidation of / Colophony, allergy of / Sensitizing potency