| 摘要 |
Compounds of the general formula I <CHEM> in which X denotes a halogen atom; Y denotes a hydrogen atom, a halogen atom, or a moiety of the general formula II <CHEM> Z denotes a halogen atom, a hydroxy group, a substituted hydroxy group, an -S(O)nR<5> group, or an -Se(O)mR<5> group; n denotes 0, 1 or 2, preferably 0 or 1; m denotes 0 or 1; R<3> denotes a hydrogen atom or an organic group; R<4> denotes a hydrogen atom, a carboxy-salt-forming ion, or a carboxy-ester-forming group; R<5> denotes a hydrogen atom, a hydrocarbon group, or a heterocyclyl group; and R<1><2> denotes a hydrogen atom, an unsubstituted or substituted hydrocarbon group, or an unsubstituted or substituted heterocyclyl group; are novel intermediates useful in the preparation of 6-methylene-penems of the general formula X: <CHEM> c |
