(R_S)-1 (85% ee) was prepared by utilizing a porcin pancreatic lipase-promoted hydrolysis of sulfinyldiacetic acid dimethyl ester (8) which was derived from thiodiacetic acid (7). (R_S)-1 (99% ee) and (S_S)-1 (99% ee) were readily obtained by methanolysis of (R_S,S)-12 and (S_S,S)-12 with MeONa in MeOH. (R_S,S)-12 and (S_S,S)-12 were furnished by chromatographic separation of the diastereomeric mixture, obtained by oxidation of thiodiacetic mono-carboxylic acid (11) with 30% H₂O₂ followed by dehydrative condensation of the resultant sulfinyldiacetic mono-carboxylic acid with 4(S)-isopropyl-1,3-thiazolidine-2-thione. (R_S)-1 (99% ee) was successively treated with (TMS)₂NLi, Ac₂O, and TMSOTf to give a major chiral-3 product in 75% ee and in a highly chemoselective manner (chiral-3 : chiral-2=93 : 7).