A convergent asymmetric synthesis of (2S, 3R, 4S, 12′R)-3-hydroxy-2-hydroxymethyl-4-(12′-methyloctadecyl)-N-(p-tolylsulfonyl)-azetidine, a key precursor of pen
The synthesis of bis(oxazoline) dicarboxylate derivatives was investigated.Diethyl-aminosulfur trifluoride (DAST) was used as a convenient cyclization reagent i