1: 10percent aq.HCl / acetone / 0.5 h / Heating 2: 1.) phenylboric acid 2.) silica gel impregnated with 2,2-dimethyl-1,3-propandiol / 1.) benzene, reflux 2.) benzene, benzene-ethyl acetate 3: 77 percent / 10percent aq.KOH, TEBA / CH2Cl2 / 0.67 h 4: 95 percent / DMSeO / 1,2-dichloro-ethane / 3.5 h / Heating 5: 70 percent / NaOH, TEBA / tetrahydrofuran / 4 h / Ambient temperature 6: 79 percent / silver(II) dipicolinate / benzene; H2O / Ambient temperature View Scheme

potassium hydroxide in tetrahydrofuran; methanol 0.833333 h;