Process for producing azetidinones.

摘要

An azetidinone of the formula: wherein R.O.CO is a protective group for the amino group; R<2> is a protective group for the nitrogen atom of the imino compound; R<3> is an organic residue bonding through a carbon atom thereof, which is produced with industrial advantages by reacting a compound of the formula: R.O.CO.NH.CH2.CO.O.CO.OR<1> wherein R.O.CO is as defined above; CO.OR<1> is an esterified carboxyl group, with a compound of the formula: R<2>.N=CH.R<3> wherein the symbols are as defined above, or a salt thereof.