Synthesis of the glycosyl lactol moiety of halichoblelide

The enantioselective synthesis of the 2-deoxy-α-l-fucosyl lactol moiety of halichoblelide, a potent cytotoxin isolated from an actinomycete of marine origin, was achieved using a diastereoselective addition of a dithianyl anion to a chiral aldehyde intermediate and a stereoselective glycosidation of a hydroxy lactone intermediate derived from the addition product with a protected l-fucal as the key steps.