Ethanol → Dimethyldioxirane

HRID 929748Notes

Reaction equation

HRID 929748 reaction equation
[C:1]([O-:4])(=[O:3])[CH3:2].[Na+].[CH2:6](O)C.[O:9]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[C:12](=[O:13])[CH:11]([C:20]2[CH:21]=[CH:22][CH:23]=[C:24]3[C:29]=2[O:28][CH:27]([C:30]2[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=2)[CH2:26][C:25]3=[O:36])[CH:10]1[C:37]1[CH:42]=[CH:41][CH:40]=[CH:39][CH:38]=1>CC(C)=O>[O:9]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[C:12](=[O:13])[CH:11]([C:20]2[CH:21]=[CH:22][CH:23]=[C:24]3[C:29]=2[O:28][CH:27]([C:30]2[CH:31]=[CH:32][CH:33]=[CH:34][CH:35]=2)[CH2:26][C:25]3=[O:36])[CH:10]1[C:37]1[CH:38]=[CH:39][CH:40]=[CH:41][CH:42]=1.[CH3:2][C:1]1([CH3:6])[O:4][O:3]1

Participants

6

Reactant 3

HCID 702EthanolHCID 517045Sodium AcetateHCID 70975504HCID 70975504, compound

Product 2

HCID 115197DimethyldioxiraneHCID 70975504HCID 70975504, compound

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

Donnelly and co-workers (Donnelly, D. M. X.; Fitzpatrick, B. M.; Ryan, S. M.; Finet, J.-P. J. Chem. Soc., Perkin Trans. I 1994, 1794-1801) synthesized the biflavonoids (46) and (47) via arylation of a 3-phenylsulfanylflavanone (48) with an 8-triacetoxyplumbylflavan derivative (49) (2:1 mixture of cis and trans). The dioxolane ring, of the intermediate (50) was cleaved during acid workup. Desulfurization of the intermediate (50) with nickel boride (NaBH4/H2O, NiCl26H2O/EtOH) yielded a chalcone (51) (in a 1.1:1 ratio of E/Z) that was cyclised with anhydrous sodium acetate in refluxing ethanol to the 3,8-biflavanone (46) in 73% yield (only the 2,3-trans isomer was isolated from a mixture of diastereoisomers with an α/β ratio of 1.4:1). Oxidation of (46) with dimethyldioxirane in acetone yielded (47) in 47% yield (Scheme 3). The end products are however not optically active and constitute a racemic mixture.

Workup

  1. customwas isolated from a mixture of diastereoisomers with an α/β ratio of 1.4:1)

Sources & evidence

ORD record
ord-bc62e303c20c4325b26de917caca2635
Source dataset
uspto-grants-2016_03
Patent number
US09296717B2

Reaction notes

Loading…