The Wittig condensation of benzyl phosphonate (I) with benzaldehyde (II) by means of potassium tert-butoxide in THF gives the (Z)-stilbene (III), which is regioselectively oxidized with AD-mix-alpha, methanesulfonamide and Na2CO3 in tert-butanol/water/dichloromethane yielding the (S,S)-diol (IV). The diol (IV) is converted into the dioxolane (V) by reaction with CH2Br2 by means of NaOH and cetyltrimethylammonium bromide. Finally, this compound is treated with acetic acid to eliminate the methoxymethyl protecting group.