反应详情

((1R,2S,3R,4R)-2,3-Dihydroxy-4-hydroxymethyl-cyclopentyl)-carbamic acid 9H-fluoren-9-ylmethyl ester (115 g, 310 mmol), 2,2-dimethoxypropane (360 ml, 3.10 mol) and p-toluenesulfonic acid monohydrate (118 g, 620 mmol) were dissolved in dry acetone (2.00 l). The mixture was stirred for 3.5 h at room temperature to the complete consumption of the starting material according to TLC (Silicagel Merck 60, chloroform/methanol/acetic acid 9:1+0.1% v/v/v). The resulting suspension was stirred 15 min at 0° C. and the precipitate was filtered off and washed with cold acetone. The obtained brown solid was suspended again in diethylether (800 ml) and stirred for 20 min, filtered off, washed with diethylether (400 ml) and dried 8 h under reduced pressure giving 116 g (91%) of the title compound.

1. stirringThe resulting suspension was stirred 15 min at 0° C.
2. filtrationthe precipitate was filtered off
3. washwashed with cold acetone
4. stirringstirred for 20 min
5. filtrationfiltered off
6. washwashed with diethylether (400 ml)
7. customdried 8 h under reduced pressure