The double bond of (2S, 3S)-4-penten-1,2,3-triol 28, which was readily prepared from dimethyl L-tartrate in 67% overall yield, was iodoaminated stereoselectively by treating its tris(trichloroacetimidate) with iodine monobromide. Also that of (2R, 3S)-4-penten-1,2,3-triol 84, which was produced from lactone 87 in 68% overall yield, was functionalized into amino iodide stereoselectively by cyclizing its tris(trichloroacetimidate) with iodine. After acidic hydrolysis of the cyclized products followed by protection as t-butyl carbamate, the former and the latter stereoselectivity were determined to be 37: 1 and 38: 1 in favor of (2S, 3S, 4S)- and (2R, 3S, 4S)-4-amino-5-iodo-1,2,3-triol, respectively.
Since (-)-anisomycin 30 and (+)-polyoxamic acid 31 contain the fucntional groups of carbamate 29, their syntheses were accomplished efficiently from 29. Carbamate 29 was converted into triol 112 via its protection as acetonide, aziridine formation and cuprate reaction. Cyclization of 112 into pyrrolidine 104 proceeded smoothly under Mitsunobu conditions in the presence of PPTS. The adjustment of its functional groups established the synthesis of (-)-anisomycin 30.
Monosilylation followed by acetonide formation gave iodide 116. Treatment of 116 with acetate generated oxazolidinone, of which protection and hydrolysis provided alcohol 119. The synthesis of (+)-polyoxamic acid 31 was completed by oxidation of 119 followed by acidic hydrolysis.