Diisopropylethylamine → ethyl 2-((R)-1-((S)-2-(tert-butyldimethylsilyloxy)-2-(4-cyanophenyl)ethyl)piperidin-3-yl)acetate

Participants

Reaction Steps

To a mixture of (18C)-isomer A, ethyl 2-((R)-1-((S)-2-(4-cyanophenyl)-2-hydroxyethyl)piperidin-3-yl)acetate (6.00 g, 18.96 mmol) and DIPEA (5.96 ml, 34.1 mmol) in DCM (63 mL) was added tert-butyldimethylsilyl trifluoromethane-sulfonate (5.67 ml, 24.65 mmol) slowly. The reaction was monitored with HPLC and the reaction was complete in 2 hours. The reaction mixture (a light brown solution) was quenched with water, the aqueous layer was extracted twice with DCM. The organic phase was combined, dried with Na2SO4, filtered, and concentrated. The crude material was purified with on a silica gel cartridge (330 g silica, 10-30% EtOAc/hexanes gradient) to give ethyl 2-((R)-1-((S)-2-(tert-butyldimethylsilyloxy)-2-(4-cyanophenyl)ethyl)piperidin-3-yl)acetate (8 g, 18.58 mmol, 98% yield).

Provenance & Evidence