| abstract |
A beta-lactam compound of the formula:n wherein R 1 and R 2 are, the same or different, each a hydrogen atom or a lower alkyl group, R 3 is a lower alkyl group, R 4 is a hydrogen atom, a carboxyl-protecting group or a thiolcarboxyl-protecting group, X is a hydrogen atom, a hydroxyl group or a protected hydroxyl group, Y is an oxygen atom or a sulfur atom and COZ is a carboxyl group, an activated or protected carboxyl group, a thiolcarboxyl group or an activated or protected thiolcarboxyl group, which is useful as a valuable intermediate in the stereospecific production of 1-alkylcarbapenem compounds. |