tert-butyl 2,3,3a,4,5,6,7,7a-octahydro-1H-indole-2-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Octahydro-indole-2-carboxylic acid 11b (5.0 g, 29.5 mmol, purchased from Bachem) was suspended in 200 mL of CHCl3 then cooled in a dry ice/acetone bath. H2SO4 (120 uL/mmol) was added followed by bubbling in excess isobutylene. The mixture was sealed and the ice bath removed. The mixture was stirred at RT for 12 hours. The reaction mixture was carefully unsealed after cooling and concentrated. EtOAc was added and washed with saturated sodium bicarbonate soln, brine, dried over sodium sulfate, then filtered and concentrated to give octahydro-indole-2-carboxylic acid tert-butyl ester 12b (6.65 g, 29.5 mmol, 100%). then cooled in a dry ice/acetone bath by bubbling in excess isobutylene The mixture was sealed the ice bath removed after cooling concentrated EtOAc was added washed with saturated sodium bicarbonate soln brine, dried over sodium sulfate filtered concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Octahydro-indole-2-carboxylic acid 11b (5.0 g, 29.5 mmol, purchased from Bachem) was suspended in 200 mL of CHCl3 then cooled in a dry ice/acetone bath. H2SO4 (120 uL/mmol) was added followed by bubbling in excess isobutylene. The mixture was sealed and the ice bath removed. The mixture was stirred at RT for 12 hours. The reaction mixture was carefully unsealed after cooling and concentrated. EtOAc was added and washed with saturated sodium bicarbonate soln, brine, dried over sodium sulfate, then filtered and concentrated to give octahydro-indole-2-carboxylic acid tert-butyl ester 12b (6.65 g, 29.5 mmol, 100%). then cooled in a dry ice/acetone bath by bubbling in excess isobutylene The mixture was sealed the ice bath removed after cooling concentrated EtOAc was added washed with saturated sodium bicarbonate soln brine, dried over sodium sulfate filtered concentrated

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Octahydro-indole-2-carboxylic acid 11b (5.0 g, 29.5 mmol, purchased from Bachem) was suspended in 200 mL of CHCl3 then cooled in a dry ice/acetone bath. H2SO4 (120 uL/mmol) was added followed by bubbling in excess isobutylene. The mixture was sealed and the ice bath removed. The mixture was stirred at RT for 12 hours. The reaction mixture was carefully unsealed after cooling and concentrated. EtOAc was added and washed with saturated sodium bicarbonate soln, brine, dried over sodium sulfate, then filtered and concentrated to give octahydro-indole-2-carboxylic acid tert-butyl ester 12b (6.65 g, 29.5 mmol, 100%). then cooled in a dry ice/acetone bath by bubbling in excess isobutylene The mixture was sealed the ice bath removed after cooling concentrated EtOAc was added washed with saturated sodium bicarbonate soln brine, dried over sodium sulfate filtered concentrated