7-Oxo-4-thia-1-aza[3,2,0]heptane and 7-oxo-4-thia-1-aza[3,2,0]hept-2-ene derivatives

摘要

What are disclosed are compounds, useful as intermediates in the preparation of substituted penem compounds, of the formula <IMAGE> methods for making such compounds from intermediates of the formula <IMAGE> by reaction of the latter with a nucleophilic compound, methods for making such intermediates from compounds of the formula <IMAGE> by reaction of the last-mentioned compounds with a tervalent phosphorus compound, and methods for making said last-mentioned compounds by cyclizing compounds of the formula <IMAGE> with a tervalent phosphorus compound.