Synthesis of Glycosidase‐Inhibiting Iminopolyols Via Isoxazolines^1,2

Abstract

The 1 ,3-dipolar cycloaddition of ally1 halides with chiral nitrile oxides, derived from glyceraldehyde derivatives, affords ca. 1 :1-mixtures of C5-epimeric isoxazolines. The diastereomers can be separated on a preparative scale by MPLC; the configurations at C5 are established by chemical correlation/>(-ray analysis initially, and then routinely, based on consistent, large differences of respective specific rotations. -An unexpected finding, which turned out to be the key to efficient transformation of 5-halomethyl-isoxazolines into hydroxy-pyrrolidines, is that highly stereoselective catalytic hydrogenations are feasible with proper combination of both 3-and 5-side chain structures and the catalyst system. -This (CJ + Cd-approach is extended to include dihydroxy-pyrrolidines, i. 8.

An expedient approach for the regio- and stereoselective synthesis of novel spiroindolizidines via [3+2] cycloaddition

“…1,3-Dipolar cycloadditions are fundamental processes in organic chemistry, and have taken an important place as a synthetic strategy for the synthesis of bioactive compounds [7], natural products, and alkaloids [8]. 1,3-Dipolar cycloaddition of azomethine ylides with various dipolarophiles become extremely interesting when the absolute configuration of the newly created stereocentres can be controlled in an enantio-and stereoselective manner [9,10].…”

Novel diastereoselective synthesis of spiropyrrolidine-oxindole derivatives as anti-breast cancer agents

“…3 The 1,3-dipolar cycloaddition reaction is a versatile synthetic strategy in organic chemistry for the synthesis of complex heterocyclic systems, 4 natural products and alkaloids. 5 The 1,3-dipolar cycloaddition of azomethine ylide to dienes affords pyrrolidines, which exhibit local anaesthetic, 6 antiviral, 7 potential antileukaemic 8 and anticonvulsant activities, 8 besides occurring in alkaloids. 9 These spiro compounds represent an important class of naturally occurring substances characterized by well pronounced biological properties.…”