... Abstract. β-Keto thiolesters readily undergo substitution at the α-carbon and the thiol ester group is easily removed by Ra-Ni. Download full text in PDF. Tetrahedron Letters No. 43, PP 4121 - 4124, 0040-4039/79/1022-4121002.00/0 Pergamon Press Ltd. 1979. Printed in Great Britain. ... 2. HJ Liu, HK Lai. Tetrahedron Lett. (1979), p. 1193. 3. HJ Liu, SK Attah-Poku and HK Lai, Synth. Commun., in press. 4. 4. ...