Toward a modular, bidirectional synthesis of (−)-mucocin

A convergent stereoselective synthesis of the C13-C34 fragment of (−)-mucocin is described. The salient features include (a) the bidirectional synthesis of the C-2 symmetric C13-C21 subunit, (b) regio- and stereoselective preparation of a 1,3-diol derivative from a diene activated by NBS via intramolecular nucleophilic sulfinyl group participation, (c) utilizing the self-metathesis reaction to prepare a functionalized C10 alkene, and (d) regio- and stereoselective intermolecular epoxide opening to construct the ether bond between C20 and C24. An organocatalytic α-hydoxylation has been employed to create the C4 stereogenic center of C1-C12 subunit. Attempted union of the two subunits utilizing the B-alkyl Suzuki coupling did not succeed.