To a stirred solution of [(R)-1-formyl-3-(4-heptyloxy-phenyl)-1-methyl-propyl]-carbamic acid tert-butyl ester (103 mg, 0.26 mMol) in tert-butanol (1 ml) and 10% aqueous KH2PO4 (1 ml) is added 2-methyl-2-butene (0.66 ml, 5.27 mMol) and sodium chlorite (59 mg, 0.52 mMol). The mixture is stirred at RT for 1 hour. The reaction mixture is then poured onto a biphasic mixture of AcOEt and HCl (aqueous, 1M). The aqueous phase is extracted twice with AcOEt. The combined organic layers are washed with a small amount of NaHCO3 (saturated aqueous solution), dried (Na2SO4) and concentrated under reduced pressure. Column chromatography eluting with 5% MeOH in CH2Cl2 gives the title compound as a colourless oil.
