A bifunctional pyrazolone–chromone synthon directed organocatalytic double Michael cascade reaction: forging five stereocenters in structurally diverse hexahydroxanthones.
DOI Number:
10.1039/C9QO00265K
Reaction Category:
Educt:
substituted 5-methyl-4-((4-oxo-4H-chromen-3-yl)methyl)-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, substituted tert-butyl (E)-2-(1-acetyl-2-oxoindolin-3-ylidene)acetate or substituted tert-butyl (E)-2-(2-oxobenzofuran-3(2H)-ylidene)acetate, substituted tert-butyl (3S,3'S,4a'S,9a'R)-1-acetyl-3''-methyl-2,5'',9'-trioxo-1''-phenyl-1'',4a',5'',9a'-tetrahydro-1'H,3'H,9'H-dispiro[indoline-3,4'-xanthene-2',4''-pyrazole]-3'-carboxylate or substituted tert-butyl (3S,3'S,4a'S,9a'R)-3''-methyl-2,5'',9'-trioxo-1''-phenyl-1'',4a',5'',9a'-tetrahydro-1'H,2H,3'H,9'H-dispiro[benzofuran-3,4'-xanthene-2',4''-pyrazole]-3'-carboxylate
Product:
substituted tert-butyl (3S,3'S,4a'S,9a'R)-1-acetyl-3''-methyl-2,5'',9'-trioxo-1''-phenyl-1'',4a',5'',9a'-tetrahydro-1'H,3'H,9'H-dispiro[indoline-3,4'-xanthene-2',4''-pyrazole]-3'-carboxylate or substituted tert-butyl (3S,3'S,4a'S,9a'R)-3''-methyl-2,5'',9'-trioxo-1''-phenyl-1'',4a',5'',9a'-tetrahydro-1'H,2H,3'H,9'H-dispiro[benzofuran-3,4'-xanthene-2',4''-pyrazole]-3'-carboxylate
Catalyst:
N-[3,5-Bis(trifluoromethyl)phenyl]-N′- [(8α,9S)-6′-methoxycinchonan-9-yl]thiourea
Cas No:
852913-16-7
Associated Product from Buchler GmbH:
Quinine Base
Cas No:
130-95-0