A Syn the sis of Tha lid o mide

b* ( ) a In sti tute of Bi o log i cal Chem is try, Ac a de mia Sinica, Nankang, Tai pei 115, Tai wan, R.O.C. b De part ment of Chem is try, Na tional Sun Yat-Sen Uni ver sity, Kaohsiung 804, Tai wan, R.O.C.