NEW MATERIAL: A compound of formula I [R1-R3 are each alkyl, substituted alkyl, alkoxy, alkenyl, phenyl, amino, etc.; R4 is formula II, formula III (M+ is H, ammonium or alkali metal)].

EXAMPLE: [1S-[1α(R*),3β,4aα,7β,8β(2S*,4S*),8aβ]]-2-methylbutanoic acid decahydro-7-methyl-3-[2-oxo-2-[(phenylmethyl)amino]ethoxy]-8-[2-(tetrahydro-4- hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1-naphthalenyl ester.

USE: Anti-hypercholesterolemic agents. Useful for treatment of arteriosclerosis, hyperlipidemia, etc.

PROCESS: The compound of formula I is obtained by amide formation of a compound of formula IV with a suitable activated carboxylic acid in a solvent such as tetrahydrofuran, etc.