98809-68-8

Upstream product

• 185-70-6 1-oxaspiro(2.5)octane 

Relevant academic research and scientific papers

Dispiro-1,2,4-trioxane analogues of a prototype dispiro-1,2,4-trioxolane: Mechanistic comparators for artemisinin in the context of reaction pathways with iron(II)

Single electron reduction of the 1,2,4-trioxane heterocycle of artemisinin (1) forms primary and secondary carbon-centered radicals. The complex structure of 1 does not lend itself to a satisfactory dissection of the electronic and steric effects that influence the formation and subsequent reaction of these carbon-centered free radicals. To help demarcate these effects, we characterized the reactions of achiral dispiro-1,2,4-trioxolane 4 and dispiro-1,2,4-trioxanes 5-7 with ferrous bromide and 4-oxo-TEMPO. Our results suggest a small preference for attack of Fe(II) on the nonketal peroxide oxygen atom of 1. For 4, but not for 5 and 6, there was a strong preference for attack of Fe(II) on the less hindered peroxide bond oxygen atom. The steric hindrance afforded by a spiroadamantane in a five-membered trioxolane is evidently much greater than that for a corresponding six-membered trioxane. Unlike 1, 5-7 fragment by entropically favored β-scission pathways forming relatively stable α-oxa carbon-centered radicals. These data suggest that formation of either primary or secondary carbon-centered radicals is a necessary but insufficient criterion for antimalarial activity of 1 and synthetic peroxides.

A Rapid Route to Medium to Large Ring Lactones via the Thermolysis of Dispiro-1,2,4-trioxane Derivatives

Dispiro-1,2,4-trioxane derivatives 3, on thermolysis in decane at 190 deg , afford either oxalactones 4, or ketolactones 5, or mixtures of both as the predominant ring-expansion products depending on the respective natures of the dispiro substituents.

Tin(IV) chloride promoted reaction of oxiranes with hydrogen peroxide

A group of substituted oxiranes were readily transformed to the corresponding β-hydroxyhydroperoxides (HHP) in good yields in ethereal SnCl4-H2O2 system in which SnCl4 acts as catalyst. Alternatively, treating oxiranes with SnCl4 first, followed by addition of ethereal H2O2 solution achieved primary gem-dihydroperoxides (DHP) in moderate yields. In the case of preparing DHP, SnCl4 first promoted the rearrangement of oxiranes to aldehydes, followed by condensation with hydrogen peroxide to provide DHP as final products. Georg Thieme Verlag Stuttgart · New York.

Facile ring-opening of oxiranes by H2O2 catalyzed by phosphomolybdic acid

At ambient temperature, in the presence of catalytic amounts of phosphomolybdic acid (PMA), ethereal hydrogen peroxide reacted readily with a range of epoxides, giving corresponding β-hydroxyhydroperoxides in high yields.

Dispiro-1,2,4-Trioxanes as Precursors of Medium Ring Lactones: Thermolysis of Indan-2-spiro-3'-(1',2',4'-trioxane)-6'-spiro-1''-cyclohexane

Thermolysis of the dispiro-trioxane (2) in decane at 190 deg C afforded a novel nine-membered ring lactone whose structure has been determined by X-ray crystallography.