| 摘要 |
Cpds. (I) and their salts: (where R1 is H or 1-4C alkyl, R2 is H, Cl, 1-3C alkyl or alkoxy and R3 is H, Cl, Br, 1-3C alkyl or -alkoxy or R3 is F or CF3 when R2 is H) are prepd. by oxidation of the tetrahydrothiophen-3-one esters followed opt. by hydrolysis of (I R1 = alkyl) to (I R1 = H or a cation). Thus. (I, R1=Et, R2=R3=H) is prepd. from the tetrahydrothiophen-3-one ethyl ester by oxidation with H2O2. |
