. . "e referred to as \"syn isomer and the other compounds having the alternative oneshown by the formula (A') as anti isomer in this specification.Suitable pharmaceutically acceptable salts of the object compounds (I) are conventional non-toxic salts and may include an inorganic salt, for example, a metal salt such as an alkali metal salt (e.g., sodium salt, potassium salt, etc.) and analkaline eart" . . . .