Synthesis of chromones and 4-hydroxyquinolines based on uncatalyzed condensations of 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with 2-alkoxy- and 2-nitrobenzoyl chlorides and related reactions.
The reaction of 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with 2-methoxybenzoyl chlorides afforded 3,5-diketoesters which were transformed, by treatment with boron tribromide, into functionalized 2-hydroxychroman-4-ones or chromones. The reaction of 1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene with 2-nitrobenzoyl chlorides and subsequent reduction of the nitro group afforded functionalized 4-hydroxyquinolines. Their tautomeric equilibrium was studied by NMR spectroscopy and by computational methods.
Rahn
Thomas
T
Institut für Chemie, Universität Rostock, Albert-Einstein-Str., 3a, 18059, Rostock, Germany.
Appel
Bettina
B
Baumann
Wolfgang
W
Jiao
Haijun
H
Börner
Armin
A
Fischer
Christine
C
Langer
Peter
P
D002070:Butadienes / Q000737:chemistry*; D002384:Catalysis; D002867:Chromones / Q000138:chemical synthesis*; D006912:Hydroxyquinolines / Q000138:chemical synthesis*; D015394:Molecular Structure; D009579:Nitrobenzoates / Q000737:chemistry*; D014297:Trimethylsilyl Compounds / Q000737:chemistry*
C543503:1-methoxy-1,3-bis(trimethylsilyloxy)-1,3-butadiene; D002070:Butadienes; D002867:Chromones; D006912:Hydroxyquinolines; D009579:Nitrobenzoates; D014297:Trimethylsilyl Compounds; C034010:4-hydroxyquinoline