Acetic Anhydride → Chroman

Participants

Reaction Steps

4-Chromanol (Aldrich) (2.77 g, 18.4 mmol) was taken up in acetic anhydride (3.5 ml, 36.9 mmol) and acetic acid (30 ml) and refluxed for 3 h, and then allowed to cool to room temperature over 16 h. 10% w/w Pd/C was then added to the solution and the whole hydrogenated at 40 p.s.i. hydrogen pressure for 16 h. The catalyst was filtered through a pad of Arbocel and the filtrate evaporated to low (5 ml) volume. The remaining liquid was dissolved in EtOAc (30 ml) and washed with water, then NaHCO3 solution (100 ml of each). The organic layer was dried over MgSO4 and evaporated to a pale yellow oil. This oil was columned in 10% EtOAc/pentane to give the title product (2.1 g, 85%);

Provenance & Evidence