1: 97 percent / 2,6-di-tert-butyl-4-methylphenol / diisopropyl ether; H2O / 5 h / Ambient temperature; lipase PS (Pseudomonas sp.) 2: 96 percent / pyridine / CH2Cl2 / 21 h / Ambient temperature 3: 88 percent / dimethylsulfoxide / 24 h / 90 °C 4: 100 percent / aq. LiOH / tetrahydrofuran / 17 h / Ambient temperature 5: 93 percent / 2 M NaOH / 2 h / Heating View Scheme

phosphoric acid; acetone