Methylene-6,7-dioxo-3,3-dimethyl-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate pivalate → HCID 86740058, compound

Participants

Reaction Steps

A solution of 6.6 g of methylene-6,7-dioxo-3,3-dimethyl-4-thia-1-azabicyclo[3.2.0]heptane-2-carboxylate pivalate in 150 ml of benzene is treated at room temperature with 11 g of ethoxycarbonyl(methoxyimino)acetylmethylenetriphenylphosphorane. After 10 minutes, the reaction mixture is evaporated. The residue is chromatographed on silica gel while eluting with cyclohexane/ethyl acetate (6:4). There is obtained methylene-(2S,5R)-6-[3-ethoxycarbonyl)-2-(Z)-(methoxyimino)acetonylidene]-3,3-dimethyl-7-oxo-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylate pivalate as an orange oil [Rf: 0.51; cyclohexane/ethyl acetate (6:4); NMR (CDCl3), δ (ppm): 1.23 (9H); 1.37 (m, 3H); 1.53 (3H); 1.62 (3H); 4.21 (3H, --OCH3); 4.42 (m, 2H); 4.65 (1H3); 5.9 (m, 2H); 6.11 (1H); 6.66 (1H)].

Provenance & Evidence