| 摘要 |
PURPOSE:To readily and highly stereoselectively obtain the subject compound which is a synthetic raw material for carbapenem compounds useful as an antimicrobial agent in good yield by subjecting a new compound as a raw material to condensation cyclizing reaction and then, as necessary, eliminating protecting groups of OH, etc. CONSTITUTION:Carboxylic acids expressed by formula I (R<2> is protecting group of OH) are made to react with a compound expressed by formula II (R<3> is lower alkyl) to produce a compound expressed by formula III, which is subsequently reacted with a tin(II) triflate in the presence of a base to provide an enolate. The resultant enolate is then reacted with acetaldehyde to afford a compound expressed by formula IV. The OH of the obtained compound expressed by formula IV is subsequently protected to afford a compound expressed by formula V (R<11> is R<2>), which is then allowed to react with a 4-lower alkoxyphenylamine to produce a compound expressed by formula VI (R<4> is R<3>). The protecting group R<2> of the OH is subsequently eliminated therefrom to form a new compound expressed by formula VII which is a raw material. The resultant compound expressed by formula VII is then subjected to condensing reaction and, as necessary, the protecting group of OH or the 4-lower alkoxyphenyl group or both are eliminated to afford the objective compound expressed by formula VIII. |
