PROCESS FOR PREPARATION OF 4-N-SUBSTITUTED AMINO-2-AZA-1-OXABICYCLO 3.3.0 OCT-2-ENE-6-CARBOXYLIC ACID ESTERS AND PROCESS FOR PREPARATION OF THEIR INTERMEDIATES

摘要

4-N-substituted amino-2-aza-1-oxabicycloÄ3.3.0Üoct-2-ene-6-carboxylic acid esters are produced by adding a Bronsted acid to a mixture of a 2-azabicycloÄ2.2.1Ühept-5-en-3-one and an alcohol, thereby causing these components to react with each other to give a salt of cis-4-amino-2-cyclopentene-1-carboxylic acid ester, then allowing the salt of cis-4-amino-2-cyclopentene-1-carboxylic acid ester thus obtained to react with an amino-protecting group introducing compound in the presence of a base, thereby giving cis-4-N-substituted amino-2-cyclopentene-1-carboxylic acid ester, and then allowing this cis-4-N-substituted amino-2-cyclopentene-1-carboxylic acid ester to react with a hypohalogenite and an aldoxime.