Functionalisation of Artemisinin and Its Ring-contracted Derivatives

Abstract

Isoxazoline analogues of artemisinin were obtained in low yield and low diastereoselectivity from the 1,3-dipolar cycloaddition of nitrile oxides. Alternatively, starting from the aldehyde 7, a number of transformations - Wittig reaction and reduction, Henry reaction and cyanohydrin formation - were achieved in significantly higher yields. In the cases where a new stereocenter was introduced this occured diastereoselectively.

Keywords

• Artemisinin
• ring contraction
• aldehyde
• 1
• 3-dipolar cycloaddition
• nitrile oxide