Sodium hydride → benzyl ((3S,4R)-1-(2,4-dimethoxybenzyl)-2-oxo-4-(2-oxoethyl)azetidin-3-yl)(4-methoxybenzyl)carbamate

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Reaction Conditions

Reaction Steps

To a solution of benzyl ((2R,3S)-1-(2,4-dimethoxybenzyl)-2-((E)-2-methoxyvinyl)-4-oxoazetidin-3-yl)carbamate (example 82, step 1, 1.44 g, 3.38 mmol) in DMF (33.8 ml) at −10° C. (salt-ice bath) was addeds sodium hydride (60%, 162 mg, 4.05 mmol). After stirring for 30 min, p-methoxybenzylchloride (506, μL, 3.71 mmol) was added. After warming to 0° C. and stirring for an additional 30 min, it was quenched with NH4Cl (aq, satd) then diluted with EtOAc and LiCl (5% aq). The layers were separated and aqueous layer was extracted with EtOAc (2×). The combined organic layers washed with LiCl (5% aq), brine, dried over Na2SO4 and concd in vacuo. The crude material was subjected to conditions described in example 82, step 2 then purified via silica gel chromatography (EtOAc-Hept, 0-70%) to afford the title compound (684 mg, 38%). LCMS: Rt=0.97 min, m/z=533.2 (M+1) Method 2m_acidic.

Provenance & Evidence