Synthesis of anellated carbasugars from (--)-quinic acid.
(3R,4R,5R)-3-[(tert-Butyl-dimethylsilyl)oxy]-4,5-(isopropylidenedioxy)-1-cyclohexanone (2) reacted with carbon disulfide and methyl iodide in the presence of sodium hydride to furnish (3R,4R,5R)-5-[(tert-butyl-dimethylsilyl)oxy]-3,4-(isopropylidenedioxy)-2-[bis(methylthio)methylene]-1-cyclohexanone (3). 2 and N,N-dimethylformamide dimethyl acetal afforded (2E,3R,4R,5R)-5-[(tert-butyl-dimethylsilyl)oxy]-2-(dimethylaminomethylene)-3,4-(isopropylidenedioxy)-1-cyclohexanone (4). These push-pull activated methylenecyclohexanones 3 and 4 underwent a ring closure reaction with hydrazine hydrate and methylhydrazine, respectively, to give pyrazoloanellated carbasugars. Treatment of 3 with formamidinium, acetamidinium and benzamidinium salts, respectively, in the presence of sodium methanolate yielded three (5R,6R,7R)-7-[(tert-butyl-dimethylsilyl)oxy]-5,6,7,8-tetrahydro-5,6-(isopropylidenedioxy)benzo[d]pyrimidines.
Herrera
Lidcay
L
Fachbereich Chemie, Universität Rostock, D-18051, Rostock, Germany.
Feist
Holger
H
Michalik
Manfred
M
Quincoces
José
J
Peseke
Klaus
K
D002241:Carbohydrates / Q000138:chemical synthesis* / Q000737:chemistry; D018716:Molecular Mimicry; D015394:Molecular Structure; D011801:Quinic Acid / Q000737:chemistry*; D013237:Stereoisomerism
D002241:Carbohydrates; D011801:Quinic Acid