Highly stereoselective directed reactions and an efficient synthesis of azafuranoses from a chiral aziridine

• DOI: 10.1039/c3ob27390c
• Publication Date: 2013-02-26T09:40:53Z
• Authors: Hogyu Lee; Jun Hee Kim; Won Koo Lee; Jaeheung Cho; Wonwoo Nam; Jaedeok Lee; Hyun-Joon Ha
• Keywords: Aziridine; Epimer; Conjugate; Stereoisomerism; Natural product

Polyhydroxylated pyrrolidines, such as biologically important azafuranoses represented by the natural product (+)-2,5-imino-2,5,6-trideoxy-gulo-heptitol and its C(3)-epimer, were elaborated from a commercially available enantiomerically pure (2R)-hydroxymethylaziridine highly stereoselective directed reactions in more than 61% overall yield. At first, nucleophile 2-trimethylsilyloxyfuran was to (2R)-aziridine-2-carboxaldehyde ZnBr2 yield unusual anti-addition single isomer via chelation-controlled transition. The ring opening of aziridine followed conjugate addition give cis-fused bicycle, which converted target molecule after required reductive operations.