The total synthesis of the pyrimidinylpropenamide antibiotics sparsomycin and sparoxomycins A1 and A2 has been achieved. The synthesis of sparsomycin relies on the iterative nucleophilic attack of sulfenate anions on alkyl halides to construct the dithioacetal monoxide chain with high diastereoselectivity. Subsequently, the reagent-controlled diastereoselective oxidation of the terminal sulfide moiety of sparsomycin directly provides sparoxomycins A1 and A2.