520 mg of the product from example 1 were dissolved in 20 ml CHCl3. 213 mg tosyl chloride and 13 mg 4-dimethylaminopyridine were added and the mixture was cooled to 5° C. 166 mg pyridine were added dropwise and stirring was continued at room temperature for 3 hrs. The mixture was stirred 1 hr at 60° C., then another 105 mg tosyl chloride were added and stirring was continued at room temperature for 16 hrs. The mixture was diluted with 50 ml CHCl3 and washed with 0.5 M HCl, dried and evaporated. Chromatography on silica yielded 180 mg of the title compound.
