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Kijanose is one of the most highly functionalized deoxysugars found in nature and a challenging synthetic target. We found that the ring opening of trisubstituted, 2-oxazolidinone-fused aziridines is regio-and stereoselective, and the azide adduct has the same stereochemistry as that of kijanose after converting the azido to a nitro group. Therefore, both αand β-methyl Lkijanosides were prepared from ethyl L-lactate in 14% total yield. O riginally isolated from the acidic hydrolysis of an antibiotic kijanimicin (2), 1−3 D-methyl kijanosides (1) are one of the most highly functionalized sugars found in nature (Figure 1). 4 Kijanimicin and its related compounds, including tetrocarcins, 5−9 arisostatins, 10,11 lobophorins, 12−18 and microsporanates, 19 belong to the family of spirotetronate antibiotics, 20−23 in which kijanose is the common nitrosugar linked to the polycyclic aglycone (tetronolide). More than 60 spirotetronate antibiotics have been isolated, and most of these compounds also exhibit antitumor or other biological activities that have therapeutic potential. 24−31 However, the synthesis or modifications of the spirotetronates rely heavily on enzymatic synthesis or semisynthesis, as the preparations and linkages of the aglycone and the deoxysugars remain a challenging task. 32−37 All of the reported chemical syntheses of methyl α-D-kijanoside start from monosaccharides, require more than 10 steps, and often encounter regio-or stereoselectivity issues (Scheme 1). 38−42 On the contrary, the identified gene cluster for the biosynthesis of kijanimicin suggests that 10 enzymes are