Frishauf, Holtz, Goodman & Woodward
Tetrahydrothiophene derivatives
 A compound of the formula [I] and pharmaceutically acceptable salts thereof; and a synthetic intermediate represented by the formula [II] and pharmaceutically acceptable salts thereof, ##STR1## wherein R 1 is hydrogen or lower alkyl; PA1 R 2 is hydrogen or a protective group of thiol; PA1 R 3 is hydroxy, a remainder of ester group or a remainder of amido group; PA1 A is straight or branched lower alkylene, and PA1 the sulfur atom in the side chain may be directly join with --CO-- to conform a thiolactone ring. The compounds of this invention have excellent thymulin-like activities and are expected to be useful for treatment of various immune disorders such as immunodeficiency and autoimmune diseases. 
Santen Pharmaceutical Co., Ltd.
C A A C C Y
C07D A61P A61P C07D C07D Y02P
inventional inventional inventional inventional inventional additional
Koji Hiroshi Masataka Shiro Nobuharu Yoichi
Yoneda Suhara Morishita Mita Kato Kawashima