Pyrane derivatives as both ACE-and NEP-inhibitors

A compound of the formula

• wherein
• R represents hydrogen, lower alkyl, carbocyclic or heterocyclic aryl-lower alkyl or cycloalkyl-lower alkyl;
• R1 represents hydrogen, cycloalkyl, carbocyclic or heterocyclic aryl, or biaryl;
• alk represents lower alkylene;
• R3 represents hydrogen or acyl;
• R4 represents oxacycloalkyl, (thia-, oxothia- or diooxothia)-cycloalkyl, azacycloalkyl, or oxacycloalkyl-, (thia-, oxothia- or diooxothia)-cycloalkyl- or azacycloalkyl-lower alkyl;
• R5 represents hydrogen or lower alkyl;
• R6 represents lower alkyl, carbocyclic or heterocyclic aryl, (carbocyclic or heterocyclic aryl)-lower alkyl, cycloalkyl, cycloalkyl-lower alkyl, biaryl or biaryl-lower alkyl;
• R7 represents lower alkyl, (carbocyclic or heterocyclic aryl)-lower alkyl, cycloalkyl-lower alkyl or biaryl-lower alkyl;
• or
• R6 and R7, together with the carbon atom to which they are attached, represent 3- to 10-membered cycloalkylidene which may be substituted by lower alkyl or aryl-lower alkyl or may be fused to a saturated or unsaturated carbocyclic 5- to 7-membered ring;
• or 5- or 6-membered (oxacycloalkylidene, thiacycloalkylidene or azacycloalkylidene), each optionally substituted by lower alkyl or aryl-lower alkyl;
• or 2,2-norbonylidene;
• COOR2 represents carboxyl or carboxyl derivatized in form of a pharmaceutically acceptable ester;
• a disulfide derivative derived from a said compound wherein R3 is hydrogen;
• or a pharmaceutically acceptable salt thereof.