Synthesis
General procedure for the synthesis of toluene-4-sulfonic acid oxetan-3-yl ester (14) from oxetan-3-ol (13) and p-toluenesulfonyl chloride:
Step 1: To a 27 mL solution of dichloromethane containing 1.00 g (13.5 mmol) of oxetan-3-ol (13) and 7.6 mL (54.0 mmol) of triethylamine, 5.15 g (27.0 mmol) of p-toluenesulfonyl chloride was added. The reaction mixture was stirred overnight at room temperature. Upon completion of the reaction, the reaction was quenched with 150 mL of saturated aqueous sodium bicarbonate and extracted with three 50 mL portions of dichloromethane. The organic phases were combined, concentrated and purified by column chromatography (silica, 0-25% ethyl acetate/hexane) to afford 1.22 g (94% yield) of toluene-4-sulfonic acid oxetan-3-yl ester (14) as a white solid. Its NMR hydrogen spectrum (CDCl3, 500 MHz) data were as follows: δ 7.78 (d, J=8.5 Hz, 2H), 7.36 (d, J=9.0 Hz, 2H), 5.29 (m, 1H), 4.69 (m, 4H), 2.46 (s, 3H).
References
[1] Patent: WO2012/138678, 2012, A1. Location in patent: Page/Page column 33
[2] Journal of Organic Chemistry, 1983, vol. 48, # 18, p. 2953 - 2956
[3] Patent: US2015/336982, 2015, A1. Location in patent: Paragraph 0290; 0291
[4] Patent: EP3342765, 2018, A1. Location in patent: Paragraph 0293
[5] Patent: US2008/9465, 2008, A1. Location in patent: Page/Page column 82
