In toluene (100 ml) were dissolved (S)-4-benzyloxy-1,2-butanediol (25.8 g, 0.132 mol), triethylamine (20.2 ml, 0.145 mol) and 4-N,N-dimethylaminopyridine (DMAP) (0.80 g, 6.58 mmol). After cooling in ice bath, trityl chloride (36.69 g, 0.1316 mol) was added to the solution and the mixture was stirred at room temperature for 10 hours. The mixture was condensed in vacuo, diluted with ethyl acetate, washed with water and then saturated brine, dried on sodium sulfate, filtered and condensed in vacuo to give (S)-4-benzyloxy-1-trityloxy-2-butanol quantitatively (55.89, yield 100%).
