192506-11-9Relevant articles and documents
Asymmetric 1,3-dipolar cycloaddition of nitrones with an electron-withdrawing group to allylic alcohols utilizing diisopropyl tartrate as a chiral auxiliary
Ding, Xia,Taniguchi, Katsumi,Hamamoto, Yoshihira,Sada, Kazunori,Fujinami, Shuhei,Ukaji, Yutaka,Inomata, Katsuhiko
, p. 1069 - 1083 (2006)
The asymmetric 1,3-dipolar cycloaddition of nitrones possessing an electron-withdrawing group to allylic alcohols was achieved by the use of diisopropyl (R,R)-tartrate as a chiral auxiliary to afford the corresponding isoxazolidines with high regio-, diastereo-, and enantioselectivity. In the case of nitrones possessing an electron-withdrawing cyano or t-butoxycarbonyl group, 1,3-dipolar cycloaddition to 2-propen-1-ol occurred to produce the corresponding 3,5-trans-isoxazolidines with high enantioselectivity. To the contrary, nitrones possessing an amide moiety afforded the corresponding optically active 3,5-cis-isoxazolidines with completely opposite diastereoselectivity. A catalytic asymmetric 1,3-dipolar cycloaddition of nitrones possessing the N,N-diisopropylamide moiety to allylic alcohols was achieved to afford di- or trisubstituted isoxazolidines with excellent enantioselectivity of up to over 99% ee. The present asymmetric 1,3-dipolar cycloaddition was applied to the synthesis for the (2S,4R)-4-hydroxyornithine derivative.
