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

An efficient and concise approach to the total synthesis of Paecilomycins E (1) and F (2), Cochliomycin C (4) and 6-epi-Cochliomycin C (3) 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.