1: 97.6 percent / potassium hydroxide, 18-crown-6 / H2O; dioxane 2: 89.1 percent / trifluoroacetic anhydride 3: 1.) mercuric acetate; 2.) sodium borohydride / 1.) water, THF, r.t. 5: 1.) ozon; 2.) dimethyl sulfide / 1.) ethyl acetate, -70 deg C 7: H2O / hydrolysis 8: aluminium chloride / C2H5SH View Scheme