A number of synthetic methods for the construction of cyclic ethers of
the type found in the brevetoxins are described. These methods includ
e cyclization reactions involving hydroxy epoxides, hydroxy dithioketa
ls and hydroxy ketones, bridging of dithionolactones and dithionoester
s, and nucleophilic additions to thionolactones. Application of this t
echnology to the total synthesis of hemibrevetoxin B is also discussed
.