反应详情

A solution of the title compound from step 10 (diastereomer mixture) (0.350 g, 0.878 mmol) and formalin (1.23 mL, 37% aqueous solution) in acetonitrile (15 mL) was mixed in portions with sodium cyanoboron hydride (0.250 g, 3.86 mmol) and stirred for 45 min at room temperature. Conc. acetic acid was then added until a neutral reaction occurred and the mixture was subsequently stirred for 45 min at room temperature. For work up the solvent was removed in a vacuum, the residue taken up in 2N NaOH (40 mL) and then extracted with ether (3×40 mL). The organic solution was dried over Na2SO4, filtered and concentrated to low volume in a vacuum. The remaining residue was purified by Chromatotron and with cyclohexane/ethyl acetate 1:1. Separation of the diastereomers could not be achieved.

1. stirringthe mixture was subsequently stirred for 45 min at room temperature
2. customFor work up the solvent was removed in a vacuum
3. extractionextracted with ether (3×40 mL)
4. dry with materialThe organic solution was dried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated to low volume in a vacuum
7. customThe remaining residue was purified by Chromatotron and with cyclohexane/ethyl acetate 1:1
8. customSeparation of the diastereomers could not