Yu, Xiao-Qiang published the artcileRhodium-catalyzed 1,4-addition of lithium 2-furyltriolborates to unsaturated ketones and esters for enantioselective synthesis of γ-oxo-carboxylic acids by oxidation of the furyl ring with ozone, Synthetic Route of 503538-69-0, the publication is Chemistry – An Asian Journal (2011), 6(3), 932-937, database is CAplus and MEDLINE.
Rhodium-catalyzed 1,4-addition of lithium 5-methyl-2-furyltriolborate ([ArB(OCH2)3CCH3]Li, Ar=5-methyl-2-furyl) to unsaturated ketones to give β-furyl ketones was followed by ozonolysis of the furyl ring for enantioselective synthesis of γ-oxo-carboxylic acids. [Rh(nbd)2]BF4 (nbd=2,5-norbornadiene) chelated with 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) or 2,3-bis(diphenylphosphino)butane (chiraphos) gave high yields and high selectivities in a range of 91-99 % ee at 30 °C in a basic dioxane/water solution The corresponding reaction of unsaturated esters, such as Me crotonate, had strong resistance under analogous conditions, but the 1,4-adduct was obtained in 70 % yield and with 94 % ee when more electron-deficient Ph crotonate was used as the substrate.
Chemistry – An Asian Journal published new progress about 503538-69-0. 503538-69-0 belongs to dioxole, auxiliary class (Atropisomeric Bisphosphine Ligands, name is (R)-5,5′-Bis(diphenylphosphino)-2,2,2′,2′-tetrafluoro-4,4′-bi-1,3-benzodioxole, and the molecular formula is C10H11N3O3S, Synthetic Route of 503538-69-0.
Referemce:
https://en.wikipedia.org/wiki/1,3-Benzodioxole,
Dioxole | C3H4O2 – PubChem