Stereoselective total synthesis of paecilomycin E and F and its two congeners Cochliomycin C and 6-epi-Cochliomycin C

<p>An efficient and concise approach to the total synthesis of Paecilomycins E (<b>1</b>) and F (<b>2</b>), Cochliomycin C (<b>4</b>) and 6-epi-Cochliomycin C (<b>3</b>) is described. The synthesis involves novel route to the synthesis of Paecilomycin E and F and further conversion to Cochliomycin C and 6-epi-Cochliomycin C. Olefin metathesis and base promoted macro lactonization being the key reactions followed by chlorination to achieve target Cochliomycin C and 6-epi-Cochliomycin C.