(5E) -13,14,18,18,19,19-hexadehydro-3-oxa-6a-carbaprostaglandin-I (2) -derivative, process for producing the same and antihypertensive agent containing the compound

摘要

1. (5E)-13,14,18,18,19,19-hexadehydro-3-oxa-6a-carba- prostaglandin-I2 derivatives of the general formula I see diagramm : EP0119949,P12,F2 in which R1 , R2 , R3 and R4 represent a hydrogen atom or an alkyl group having from 1 to 5 carbon atoms, and R5 represents an alkyl group having from 1 to 5 carbon atoms, and salts thereof with physiologically acceptable bases.