A new route for the synthesis of the cytotoxic anhydrosphingosine pachastrissamine has been developed. [3.3] Sigmatropic rearrangement of an allyl cyanate was employed to construct the allylamine moiety in 2 from the chiral C-4 unit 3. Oxidative cleavage of the double bond in 2, followed by THF ring formation furnished the target pachastrissamine.