14261-95-1Relevant academic research and scientific papers
Novel results from the sodium borohydride reduction of E-3-benzylidene- chromanone epoxides in methanol: Formation of an interesting class of chromanone-derived methoxydiols
Mandal, Tapas K.,Sepay, Nayim,Chatterjee, Nachiketa,Mallik, Asok K.
, p. 1805 - 1813 (2014/01/17)
Sodium borohydride reduction of a number of E-3-benzylidenechromanone epoxides in methanol gave an interesting class of methoxydiols characterized as 3(S*),4(S*)-dihydroxy-3-[α(R*)-methoxybenzyl]chromans, along with the corresponding cis-epoxyalcohols. Mechanistic pathway for the formation of the new type of methoxydiols has been suggested to be methoxide-induced opening of the epoxide ring of an intermediate related to the trans-epoxyalcohols. Sodium borohydride reduction of E-2-benzylidene-1-tetralone epoxide also gave similar results.
Highly enantioselective epoxidation of multisubstituted enones catalyzed by non-heme iron catalysts
Wang, Bin,Wang, Shoufeng,Xia, Chungu,Sun, Wei
supporting information; experimental part, p. 7332 - 7335 (2012/09/22)
Iron(II) efficiency: The iron complexes of N4 ligands, derived from proline and benzimidazole, exhibited an unprecedented activity and enantioselectivity for the epoxidation of a variety of di- and trisubstituted enones (see scheme). This syste
Dimethyldioxirane Oxidation of 3-Arylidenechromanones
Adam, Waldemar,Halasz, Judit,Levai, Albert,Nemes, Csaba,Patonay, Tamas,Toth, Gabor
, p. 795 - 804 (2007/10/02)
Oxidation of the (E) and (Z) isomers of the 3-arylidenechromanones 5 by isolated dimethyldioxirane (as acetone solution) at ambient temperature resulted in the formation of the spiro epoxides trans- and cis-6, respectively, in moderate yields (23-51percent), together with considerable amounts (16-40percent) of the 3-aroylchromones 7 from both (E)- and (Z)-5 isomers.Minor products, namely 3-(α-hydroxy-4-methoxy-benzyl)-4H-1-benzopyran-4-one (8b), 1a,7a-dihydro-7a-(α-hydroxy-4-methylbenzyl)-7H-oxirenobenzopyran-7-one (9d), and the 1a,7a-dihydro-7a-aroyl-7H-oxirenobenzopyran-4-ones 10a-c have also been isolated and characterized.Presumably, the formation of 3-aroylchromones 7 can be attributed to competitive allylic oxidation with dimethyldioxirane to afford first the 3-(α-hydroxyarylmethyl)chromones 8, whose secondary alcohol functionality is subsequently oxidized by dimethyldioxirane to give the 3-aroylchromones 7.Further oxidation of the latter by dioxirane affords the epoxides 10, as established by a control experiment.Alternatively, first oxidation of 8 to yield epoxide 9 and subsequent oxidation of the alcohol functionality to afford the overoxidized product 10 cannot be disposed of on grounds of our product data.Nonetheless, despite the moderate yields of the desirable chromanone epoxides 6, the stereoselective oxidation directly of the chromanones by dimethyldioxirane offers a convenient preparation.Relative configuration and stereochemistry of compounds 6-10 were elucidated by NMR spectroscopy and AM1 calculations. - Key Words: Chromanones / Dimethyldioxirane / Epoxides
