A convenient synthesis of immunosuppressive agent FTY720 (1) using the Petasis reaction was developed. 4-Octylbenzaldehyde (9) was converted into 1-ethenyl-4-octylbenzene (11) by two-step synthesis. Hydroboration of 11 using catecholborane and hydrolysis gave (E)-2- (4-octylphenyl) vinylboronic acid (4). The Petasis reaction of 4, dihydroxyacetone (3), and benzylamine following catalytic hydrogenation afforded FTY720 (1).
