Cepham-forbindelser

摘要

The present invention relates to a compound of the formula [I]: wherein A is lower alkylene or lower alkenylene; R¹ is lower alkyl, hydroxy(lower)alkyl, protected hydroxy(lower)alkyl, amino(lower)alkyl or protected amino(lower)alkyl, and R² is hydrogen or amino protecting group, or R¹ and R² are bonded together and form lower alkylene; R³ and R⁵ are independently amino or protected amino; and R⁴ is carboxy or protected carboxy, or a pharmaceutically acceptable salt thereof, a process for preparing a compound of the formula [I], and a pharmaceutical composition comprising a compound of the formula [I] in admixture with a pharmaceutically acceptable carrier.