Chloroform → 4-Oxocyclohexyl 4-methylbenzene-1-sulfonate

Participants

Reaction Steps

step 2—To a solution of 76 (2.23 g, 8.22 mmol) and CHCl3 (30 mL) was added PCC (1.77 g, 8.22 mmol) and CHCl3 (20 mL). One drop of HOAc was added and the mixture was stirred at RT for 2.5 days. An additional 1.77 g (8.22 mmol) of PCC was added and stirring continued at RT for an additional 6 h. The reaction was diluted with Et2O and filtered through a bed of SiO2. The cake was washed with Et2O and the filtrate was passed through a second plug of SiO2 while washing the cake with Et2O. The filtrate was stripped in vacuo and the crude material was purified by SiO2 chromatography eluting with a DCM/MeOH gradient (0 to 4% MeOH). The recovered material was re-purified by SiO2 chromatography eluting with a gradient of hexane/acetone (15 to 25% acetone) to afford 1.32 g (58%) of toluene-4-sulfonic acid 4-oxo-cyclohexyl ester (78) as a colorless oil: 1H NMR (CDCl3, 300 MHz): δ 7.83 (d, 2H), 7.37 (d, 2H), 4.92-4.86 (m, 1H), 2.78-2.53 (m, 2H), 2.46 (s, 3H), 2.34-2.13 (m, 4H), 2.03-1.83 (m, 2H).

Provenance & Evidence