A Short Synthesis of (+)-Brefeldin C via Enantioselective Radical Hydroalkynylation

Abstract

Av ery conciset otal synthesis of (+ +)-brefeldin C starting from 2-furanylcyclopentene is described. This approach is based on an unprecedented enantioselective radical hydroalkynylation process to introduce the two cyclopentanes tereocenters in as ingle step. The use of a furan substituent allows ah igh trans diastereoselectivity to be achieved duringt he radicalp rocess and it contains the four carbona toms C1-C4 of the natural product in an oxidation state closely relatedt ot he one of the target molecule. The eight-step synthesis requires six product purifications and it provides (+ +)-brefeldin Ci n1 8% overall yield.[**] Ap revious versiono ft his manuscript has been deposited on ap reprint server (https://doi.org/10.26434/chemrxiv.8397731.v1)Supporting information and the ORCID identification number(s) for the author(s) of this articlecan be found under: https://doi.Scheme3.Conversion of alkyne 2b into (+ +)-brefeldin C. X-ray single-crystal structureof(+ +)-brefeldin C( 50 %p robability ellipsoids).