Catalytic Asymmetric Synthesis of Isoxazolines from Silyl Nitronates
摘要:
1,3-Dipolar Cycloadditions of triisopropylsilyl intronates and 2-alkylacroleins produced isoxazolines bearing a chiral quaternary center in high yields-and enantioselectivities with the aid of a chiral oxazaborolidine catalyst. One chiral isoxazoline product was converted to (R)-(+)-Tanikolide in 9 steps in a total yield of 43%.
α-Methoxyallyl sulfides prepared from methoxy(phenylthio)methane proved to be a novel acylanionequivalent providing a new synthetic method for α-methylenated ketones.