Trifluoroacetic acid → racemic (2'R,3R,4'S)-6-chloro-4'-(3-chlorophenyl)-2'-isopropenyl-1'-hydroxycarbonylmethyl spiro[3H-indole-3,3'-piperidine]-2,6'(1H)-dione

Participants

Reaction Steps

In a manner similar to the method described in example 55d, racemic (2′R,3R,4′S)-6-chloro-4′-(3-chlorophenyl)-2′-isopropenyl-2,3-dihydro-1′-[(tert-butoxycarbonyl)methyl]-2,6′-dioxospiro[indole-3,3′-piperidine]-1-methoxyethyl trimethylsilane (2.88 g, 4.46 mmol) prepared in example 116b was reacted with trifluoroacetic acid, then ethyl-diisopropyl-amine to give racemic (2′R,3R,4′S)-6-chloro-4′-(3-chlorophenyl)-2′-isopropenyl-1′-hydroxycarbonylmethylspiro[3H-indole-3,3′-piperidine]-2,6′(1H)-dione as yellow oil (Yield 1.7 g, 85.8%).

Provenance & Evidence