Decaline based HMC-COA reductase inhibitors with two C-6 substituents

A compound selected from the group consisting of general formulae I and II:

• ##STR14## wherein:
• R.sup.1 represents a C.sub.1-8 alkyl, C.sub.3-8 cycloalkyl, C.sub.3-8 cycloalkyl(C.sub.1-8)alkyl, C.sub.2-8 alkenyl, or C.sub.1-6 alkyl substituted phenyl group;
• R.sup.2 represents C.sub.2-5 alkenyl or C.sub.2-5 alkenyl substituted with substituted phenyl group;
• R.sup.3 represents a hydrogen atom or R.sup.4 or M;
• R.sup.4 represents a C.sub.1-5 alkyl group, or a C.sub.1-5 alkyl group substituted with a group chosen from substituted phenyl, dimethylamino and acetylamino;
• R.sup.5 represents a hydrogen atom or a methyl or ethyl group;
• R.sup.6 represents a C.sub.1-8 alkyl, C.sub.2-8 alkenyl or a C.sub.2-8 alkynyl group or a C.sub.1-5 alkyl, C.sub.2-5 alkenyl or a C.sub.2-5 alkynyl group substituted with a substituted phenyl group;
• wherein the term "substituted", as applied to the phenyl group, means substituted with up to four substituents each of which independently may be C.sub.1-6 alkyl, C.sub.1-6 alkoxy, hydroxy, thiol, amino, halo (including fluoro, chloro, bromo, and iodo), trifluoromethyl or mitro;
• M represents a cation capable of forming a pharmaceutically acceptable salt;
• Q represents C.dbd.O or CHOH;
• and
• each of a, b, c, and d is independently a single or double bond except that when a and c are double bonds then b is a single bond.