Pyrroles having hypolipidemic hypocholesteremic activities, process for their preparation and pharmaceutical compositions containing them and their use in medicine

A compound of formula (I)

• their tautomeric forms, their stereoisomers, and their pharmaceutically acceptable salts, wherein R2 and R3 represent hydrogen, and R1 is methyl, R4 may be same or different, and represent hydrogen, cyano, or substituted or unsubstituted groups selected from linear (C1-C6)alkyl, branched (C1-C6)alkyl, aryl, aralkyl, heterocyclyl, heteroaryl, heterocyclyl(C1-C6)alkyl, heteroar(C1-C6)alkyl, acyl, acyloxy, mono-substituted or di-substituted aminoalkyl, alkoxyalkyl, aryloxyalkyl, aralkoxyalkyl, (C1-C6)alkylthio, thio(C1-C6)alkyl, arylthio;
• n represents an integer 2, W represents O;
• Ar represents a substituted or unsubstituted divalent single or fused aromatic, heteroaromatic group;
• R5 and R6 represent both hydrogen or together represent a bond;
• X represents O;
• R7 represents hydrogen, substituted or unsubstituted groups selected from linear and branched (C1-C12)alkyl;
• Y represents O;
• Z represents O;
• R8 represents hydrogen, substituted or unsubstituted groups selected from linear (C1-C6)alkyl and branched (C1-C6)alkyl.