3,6-Anhydro-2,4,7-trideoxy-8,9-bis-O-[(1,1-dimethylethyl)dimethylsilyl]-5-O-methyl-4-[(phenylsulfonyl)methyl]-D-glycero-D-gulo-nonose, is an intermediate in the synthesis of in the synthesis of Eribulin mesylate (E615203), a synthetic analog of the marine natural product halichondrin B.