Phthalimide → 2-(4,4-Dimethylcyclohex-2-enyl)isoindoline-1,3-dione

Participants

Reaction Conditions

Reaction Steps

Resin supported triphenylphosphine (32.7 g, 106 mmol), isoindoline-1,3-dione (17.19 g, 117 mmol), and 4,4-dimethylcyclohex-2-enol (13.4 g, 106 mmol) were combined and THF (197 mL) was added. The mixture was stirred and cooled to 0° C., then diisopropyl azodicarboxylate (21.09 mL, 107 mmol) was added drop-wise over 2 min. The reaction was stirred and allowed to warm slowly to ambient temperature overnight. The reaction mixture was filtered and then concentrated to a yellow solid under reduced pressure. Ethyl acetate (200 mL) was added and the resulting solids were filtered off again. The ethyl acetate filtrate was washed with water (100 mL), the aqueous layer extracted with ethyl acetate (100 mL), the combined organic layers were dried over anhydrous magnesium sulfate, filtered, and concentrated to an oil that was purified by silica gel chromatography (0-20% ethyl acetate/hexane) to afford 2-(4,4-dimethylcyclohex-2-enyl)isoindoline-1,3-dione (11.59 g, 45.4 mmol, 42.8% yield) as an oil. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.84 (s, 4H), 5.51-5.62 (m, 1H), 5.43 (d, J=10.15 Hz, 1H), 4.59-4.74 (m, 1H), 2.14-2.30 (m, 1H), 1.67-1.81 (m, 1H), 1.44-1.68 (m, 2H), 1.09 (s, 3H), 1.01 (s, 3H); MS (ESI) m/z 256.2 [M+1]+.

Provenance & Evidence