反应详情

Triethylamine (263 mg, 2.6 mmol) is added by syringe to a mixture of (3S,4R)-3-[(R)-1-hydroxyethyl]-4-[3-(4-nitrobenzyl)oxycarbonyl-2-oxopropyl]azetidin-2-one (253 mg, 0.72 mmol) and p-carboxybenzene sulfonylazide (196 mg, 0.84 mmol) in dry acetonitrile (6 ml) at 0° C. When addition is complete the cooling bath is removed and the reaction mixture is stirred at room temperature for 1 hour. The mixture is then diluted with ethyl acetate (50 ml) and filtered. The filtrate is concentrated in vacuo and the residue is chromatographed on a short silica gel column (ethyl acetate) to yield 222 mg, (81% overall from (3S,4R)-1-(t-butyldimethylsilyl)-3-[(R)-1-(t-butyl dimethylsilyloxy)ethyl]-4-[3-(4-nitrobenzyl)oxycarbonyl-2-oxopropyl]azetidin-2-one) of (3S,4R)-3-(R)-1-hydroxyethyl)-4-[3-(4-nitrobenzyl)oxycarbonyl-2-oxo-3-diazopropyl]azetidin-2-one as a white solid m.p. (dec.) 163° C. IR(CHCl3, CM-1) 3410, 2132, 1756, 1718, 1650, 1350, 1280, 1120; n.m.r. (CDCl3) δ7.9(2d-aromatic,4), δ5.4(s,2), δ6.2(brs,1), δ4.1(m,2), δ2.6-3.6(m,4), δ1.32(d,3,J=6.2).

1. additionWhen addition
2. customis removed
3. additionThe mixture is then diluted with ethyl acetate (50 ml)
4. filtrationfiltered
5. concentrationThe filtrate is concentrated in vacuo
6. customthe residue is chromatographed on a short silica gel column (ethyl acetate)