Additional cycle formation from 2-dialkoxyphosphonylmethylthiazole

Abstract

Diisopropoxyphosphonyl-2-(4-methylthiazolyl)methane I reacts with carbonyl and α-halocarbonyl compounds by three routes. In the case of Knoevenagel or Horner-Wadsworth-Emmons reactions the corresponding ethylenes were produced, whereas employing α-halocarbonyls as partners resulted in pyrrolo[2.1b]thiazoles. 1-Phosphonyl-1-(2-thiazolyl)-ethylene undergoes smoothly [4+2] and [3+2] cycloaddition reactions.