Synthesis of Chloramphenicol via a New Intermediate 4-para-Nitrophenyl- 5-formamido-1,3-dioxane.

Abstract 4-Phenyl-5-amino-1,3-dioxane 4, obtained from β-bromo styrene 2 was protected as formamido derivative 5. Nitration of 5 followed by regioselective acylative cleavage of the nitro product 12 gave N-formyl-N-acetyl hemiacetal diacetate 16, which on sequential base and acid hydrolysis followed by dichloroacetylation gave chloramphenicol 1.