Synthesis of new asymmetric phosphonylated thiazolines and their use in olefination reactions

N-(2-Hydroxyalkyl)-2-phosphonoethanethioamides were prepared from a readily accessible phosphonodithioacetate and commercial chiral beta-amino alcohol s. Taking advantage of both the presence of the hydroxy group (nucleofuge) and of the C=S (nucleophile) in the same molecule, we obtained new chiral p hosphonylated thiazolines by an intramolecular cyclisation using the Mitsun obu procedure. These thiazoline-phosphonates were then involved in Worner-W adsworth-Emmons reaction to give asymmetric vinylic thiazolines.