LEE, WS MAH, HD NAM, KD KANG, SB 2024-01-21T23:11:17Z 2024-01-21T23:11:17Z 2021-09-02 1992-02-20 0253-2964 https://pubs.kist.re.kr/handle/201004/146466 The ring expansion of 1,3-thiazolidines 4 derived from beta-ketoacid derivatives to the corresponding dihydro-1,4-thiazines 1 by using the action of chlorine on 4 has been achieved. In the chlorinolysis unisolable sulfenyl chlorides 5 may be formed from chlorosulfonium ions 11 by beta-elimination involving carbonyl activated methylene hydrogens. Addition of sulfenyl chloride to the internal double bond appears to form probable thiiranium ions 14, which in turn gave 1 with loss of acidic proton. Imminium ions 15 could be hydrolyzed easily to give enol 8. As a side reaction, dihydrothiazine that was formed was further chlorinated to produce dichlorides 16 which were rearranged readily to the chloromethyl compounds 10. English KOREAN CHEMICAL SOC DIHYDRO-1,4-OXATHIINS CONVERSION OF 1,3-THIAZOLIDINES TO DIHYDRO-1,4-THIAZINE BY CHLORINOLYSIS Article 1 BULLETIN OF THE KOREAN CHEMICAL SOCIETY, v.13, no.1, pp.83 - 87 BULLETIN OF THE KOREAN CHEMICAL SOCIETY 13 1 83 87 scie A1992HH04800025 Chemistry, Multidisciplinary Chemistry Article DIHYDRO-1 4-OXATHIINS ring expansion 1,3-thiazolidines dihydro-1,4-thiazines chlorinolysis sulfenyl chloride