(5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-(2,4-dimethoxybenzyl)-3-methylpiperidin-2-one → (3S,5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-methylpiperidin-2-one

Participants

Reaction Steps

A solution of (5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-1-(2,4-dimethoxybenzyl)-3-methylpiperidin-2-one (Example 71, Step C, mixture of diastereomers) (105.87 g, 202 mmol) in TFA (778 mL, 1.01E+04 mmol) was heated at 50° C. for 2 hours before concentrating the reaction mixture in vacuo. The residue was azeotroped with hexanes to remove all of the TFA. The deep purple oil containing some residue was taken up in a minimum amount of DCM, filtered and washed liberally with DCM. The filtrate was concentrated in vacuo to provide a dark purple oil. Purification (wet packed with a minimum amount of DCM) using the Biotage Isolera (Biotage, Charlotte, N.C.) with a 1.5 kg column and eluting with 25-40% EtOAc/hexanes provided the title compound as a white solid.

Provenance & Evidence