760175-74-4

Upstream product

• 74418-34-1 4β-(Hydroxymethyl)-thujan-3-one 
• 76231-76-0 (1S,5R)-1-isopropyl-4-methylbicyclo[3.1.0]hexan-3-one 
• 471-15-8 Thujone 
• 760175-72-2 4-methoxymethyl-α-thujone 

Relevant academic research and scientific papers

α- and β-thujone radical rearrangements and isomerizations. A new radical clock

Radical clocks have been extensively used in chemical and biochemical mechanistic studies. The C4 radicals of α- and β-thujone can undergo two distinct rearrangement reactions that could, in principle, serve as simultaneous but independent radical clocks. We have therefore generated these C4 radicals by photolysis of the corresponding N-hydroxypyridine-2-thione ester precursors and have investigated their fates and lifetimes. Photolysis of either α- or β-thujone generates the same 6:100 mixture of α- and β-thujone when the radicals are quenched by thiophenol. Hydrogen atom transfer from thiophenol to the radical thus occurs preferentially from the less sterically hindered α-face to give β-thujone. The third product formed in the photolysis via opening of the cyclopropyl ring is 2-methyl-5-isopropylcyclopent-2-enone. The ratio of ring opened to unopened products gives very similar values of krα = 4.4 × 10 7 S-1 and krβ = 1.0 × 108 S-1 for ring opening of the radicals generated from α- and β-thujone, respectively. If the C4 cation rather than radical is generated, it is converted to carvacrol, a phenol that is not obtained in the radical reactions. Thujone therefore differentiates between radical and cation pathways and provides a measure of the radical lifetime.

Reaktionen des (+)-Thujons und (-)-Isothujons mit Formaldehyd

(+)-Thujone and (-)-isothujone react with formaldehyde to give 4β-(hydroxymethyl)thujone (1) and the 2-methylene derivatives 6 and 7.Oxidation of 1 gives thujone-4β-carboxylic acid (2) which decarboxylates to (+)-thujone. 1 is reduced to the isomeric 4β-(hydroxymethyl)- (3a, 3b) and 4-methylthujanols (4a, 4b). 3-Methylthujanol is oxidized to 4-methylthujone (5).

EPIMERISIERUNG VON (-)-THUJON ZU (+)-THUJON

(-)-Thujone is quantitatively epimerized to (+)-thujone over 4-hydroximethylthujone and thujone-4-carboxylic acid.