General procedure for the synthesis of tert-butyl (S)-(1-hydroxybut-3-en-2-yl)carbamate from tert-butyl (S)-2,2-dimethyl-4-vinyloxazolidine-3-carboxylate: To a methanol (83 mL) solution of tert-butyl (S)-2,2-dimethyl-4-vinyl-1,3-oxazolidine-3-carboxylate (1.90 g, 8.36 mmol) at 0 °C was added tert-butyl (S)-2,2-dimethyl-4-vinyl-1,3-oxazolidine-3-carboxylate (1.80 g, 8.36 mmol). ) solution was added to p-toluenesulfonic acid monohydrate (0.80 g, 4.2 mmol). The reaction mixture was slowly warmed to room temperature and stirred overnight. After the reaction was completed, the reaction mixture was diluted with saturated NaHCO3 solution and then concentrated. The mixture was extracted with ethyl acetate and the organic layer was sequentially washed twice with saturated aqueous NaHCO3 solution and then with brine. The organic layer was dried with Na2SO4, filtered and concentrated to afford the target product tert-butyl (S)-(1-hydroxybut-3-en-2-yl)carbamate as a colorless oil (1.187 g, 76% yield). The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3): δ 5.81 (1H, m), 5.25 (2H, m), 4.90 (1H, m), 4.25 (1H, br s), 3.67 (2H, m), 1.45 (9H, s) ppm.
