C(OC1[CH:12]=[CH:11][C:8]([CH:9]=[CH2:10])=[CH:7][CH:6]=1)(=O)C.[OH-].[K+].C(O[C:20]([O:22][C:23]([O:25][C:26]([CH3:29])([CH3:28])[CH3:27])=[O:24])=O)(C)(C)C>[OH-].[K+].C(O)C>[C:26]([O:25][C:23]([O:22][C:20]1[CH:10]=[CH:9][C:8]([CH:11]=[CH2:12])=[CH:7][CH:6]=1)=[O:24])([CH3:27])([CH3:28])[CH3:29]A solution comprising 0.49 grams potassium hydroxide, 40 grams of 4-acetoxystyrene, and 100 grams of absolute ethanol was refluxed for 4 hours. The reaction solution was cooled to 28° C. and 13 grams of potassium hydroxide pellets were added over a period of 10 minutes. After an additional 30 minutes of reaction, 64 grams di-tertiary-butyl-dicarbonate was charged portionwise over 20 minutes and the reaction was stirred for an additional hour at 28° C. After aqueous washing, the reaction product was extracted with ethyl acetate. The ethyl acetate was stripped from the extraction mixture on a rotary evaporator and the residual oil was charged with 0.07 grams phenothiazine. Distillation at 0.1 mm Hg gave 34.2 grams (64%) 4-tertiary-butoxycarbonyloxystyrene.
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