Thiazoles in glycosylation reactions: Novel synthesis of thiazole thioglycosides

AbstractThis research reports a novel method for synthesizing new thiazole thioglycosides. This series of thiazole thioglycosides were designed by the reaction of potassium cyanocarbonimidodithioate 2 with benzoyl acetonitrile 3a and ethyl bromoacetate 3b in the presence of ethanol‐KOH to give the corresponding potassium 4‐amino‐5‐substituted‐thiazole‐2‐thiolates 4a,b. The latter compounds were treated with peracetylated sugar bromides 6a,b in DMF to give high yields of the corresponding thiazole thioglycosides 7a‐d. Treatment of thiazole salts 4a,b with hydrochloric acid gave the corresponding 3‐mercaptothiazole derivatives 5a,b. The latter compounds were reacted with peracetylated sugars 6 in sodium hydride in DMF to produce the S‐glycosyl compounds 7a‐d. Ammonolysis of the protected thiazole thioglycosides 6a‐h gave the corresponding free thiazole thioglycosides 8a‐d. The compounds have been characterized by 13C NMR, 1H NMR, and IR.