[N+:1]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1/[CH:10]=[CH:11]/[C:12]([O:14][CH3:15])=[O:13])([O-:3])=[O:2].C[N+]1([O-])CC[O:20]CC1.[OH2:24].OS([O-])=O.[Na+]>[Os](=O)(=O)(=O)=O.C(O)(C)(C)C.CC(C)=O>[OH:24][CH:11]([CH:10]([OH:20])[C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=1[N+:1]([O-:3])=[O:2])[C:12]([O:14][CH3:15])=[O:13]
Methyl 2,3-dihydroxy-3-(2-nitrophenyl)propionate (Compound IIa) was prepared by adding 250 mg of osmium tetroxide (0.984 mmol) in one portion to a 0° C. solution of 15 g of methyl trans-3-(2'-nitrophenyl)propenoate (72.4 mmol) (Compound Ia) and 12.7 g of N-methylmorpholine-N-oxide (0.108 mol) in a solution containing 25 ml each of H2O, acetone and t-butanol (1:1:1). The reaction was warmed to room temperature, then stirred for 6 hr. Then, 50 ml of a freshly prepared solution of 20% (v/v) NaHSO3 was added slowly over 30 min to destroy excess oxidant. Several scoops of NaCl were added to the resulting reaction mixture, and then the product was extracted 3 times, each with 200 ml of ether. The combined extracts were washed with 150 ml of a saturated NaCl solution (brine), dried over MgSO4, and then concentrated in vacuo. The crude product, a light brown solid, was purified by recrystallization from ethanol to give 15.3 g (87% yield) of Compound IIa. M.p. 125.6-127.6° C.
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