Process for preparing beta-lactam derivative and synthetic intermediate thereof

摘要

Disclosed is a process for preparing a beta -lactam compound represented by the formula: wherein R<1> represents a hydroxy-substituted lower alkyl group or an amino group each of which may be protected; R<2> represents a hydrogen atom or an ester residue; X represents a methylene group which may be substituted by a lower alkyl group, a sulfur atom or a group represented by the formula: -A-CH2- where A represents a sulfur atom, an oxygen atom or a methylene group; and Y is either a W which represents an active ester residue of a hydroxyl group, or a R<4> which is an organic group, or a salt thereof, which comprises the steps of treating a corresponding 1-aza-3-thia-bicycloalkane compound represented by the formula: or a salt thereof with a base in the presence of a desulfurizing agent and then reacting the resulting compound with an active esterifying agent of hydroxyl group and, if appropriate, further treating the beta -lactam compound obtained with a R<4>-SH compound.