1,5-Diazabicyclo(5,4,0)undec-5-ene → Benzyl 3-(2-acetamidoethylsulphinyl)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate

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Reaction Steps

A solution of benzyl 3-(2-acetamidoethylsulphinyl)-3-chloro-7-oxo-1-azabicyclo[3.2.0]heptane-2-carboxylate (62) (0.010 g) in ethyl acetate (1 ml) was treated with 1,5-diazabicyclo[5.4.0]undec-5-ene (0.0037 g) under an argon atmosphere. It was stirred at room temperature for 15 minutes and then washed with brine and dried over sodium sulphate. The solution was concentrated to give benzyl 3-(2-acetamidoethylsulphinyl)-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylate (63) (0.007 g) as a colourless gum; νmax (CHCl3) 3400, 2980, 2920, 1795, 1920, 1670, 1600 and 1515 cm-1 ; νmax (ethanol) 305 nm; τ(CDCl3) 2.5-2.8 (5H, m, phenyl), 4.76 (2H, s, benzyl CH2), 5.6-5.9 (1H, m, C5-H), 6.3-7.3 (8H, m, C4-H2, C6-H2, NCH 2 CH2S) and 8.14 (3H, s, COCH3).

Provenance & Evidence