A new method for the stereoselective construction of angular methyl group of fuzed cyclic ethers
A convenient method for the stereoselective construction of angular methyl group of fuzed cyclic ethers is described. Reactions of mixed thioacetals with Me2Zn/Zn(OTf)2 afforded the corresponding methylated products in good yields. Various protective groups such as MOM ether, benzylidene acetal, TBS ether, and pivaloyl group were stable under the reaction conditions.
The convergent total synthesis of brevenal, a non-toxic brevetoxin antagonist, has been achieved.The ABC ring segment and the E ring precursor were connected by the intramolecular allylation followed by ring-closing metathesis to furnish the pentacyclic e
A total synthesis of brevenal is described. The pentacyclic ether core was constructed by the intramolecular allylation of α-acetoxy ether and subsequent ring - closing metathesis. Both of the diene side chains were introduced by Wittig olefination and a