1: 1.) p-toluene sulphonic acid; 2.) molecular sieve 4A / toluene / 1.) reflux 7 h; 2.) reflux overnight 2: sodium borohydride / methanol / 2 h / Heating 3: toluene / Heating 4: toluene / Heating 5: 50percent acetic acid / 6 h / Heating 6: 1.) Na2CO3, few cryst. KI; 2.) HCl / 24 h View Scheme

1: 1.) p-toluene sulphonic acid; 2.) molecular sieve 4A / toluene / 1.) reflux 7 h; 2.) reflux overnight 2: sodium borohydride / methanol / 2 h / Heating 3: toluene / Heating 4: toluene / Heating 5: 50percent acetic acid / 6 h / Heating 6: 1.) Na2CO3, few cryst. KI; 2.) HCl / 24 h View Scheme

hydrogenchloride; sodium carbonate 24 h;