Calcium salts of indole derived statins

A calcium salt of the formula

• wherein R1 is alkyl, cycloalkyl or aralkyl;
• R2, R3 and R4 are independently hydrogen, halogen or alkyl;
• R5 and R6 are independently hydrogen, halogen, alkyl, cycloalkyl, aralkyl, alkoxy or aralkoxy;
• and the hydroxyl group at the 3-position is in the R-configuration and at the 5-position in the S-configuration;
• or an enantiomer thereof;
• or a hydrate thereof;
• obtainable by treating an alkali metal salt of the formula
• wherein R1, R2, R3, R4, R5 and R6 have meanings as defined for formula IA;
• M represents sodium, lithium or potassium;
• and the hydroxyl group at the 3-position is in the R-configuration and at the 5-position in the S-configuration;
• or an enantiomer thereof;
• or a hydrate thereof;
• with a calcium compound to afford the calcium salt of formula IA.

A crystalline calcium salt of the formula

• wherein R1 is isopropyl;
• R2 is fluorine;
• R3, R4, R5 and R6 are hydrogen;
• and the hydroxyl group at the 3-position is in the R-configuration and at the 5-position in the S-configuration;
• or an enantiomer thereof;
• or a hydrate thereof.