p-Toluenesulfonic acid → HCID 59595152, compound

Participants

Reaction Steps

Prepared according to general procedure using (E)-tert-butyl 2-(2-hydroxyphenylcarbonyl)-3-(naphthalen-2-yl)prop-2-enoate (77 mg, 0.20 mmol), thiourea catalyst III (14 mg, 0.020 mmol) in 2.0 mL toluene for 38 h at −25° C. and p-toluenesulfonic acid (19 mg, 0.10 mmol) for 10 h. Purification via column chromatography with 10% EtOAc/hexanes afforded 49 mg (89%) of 9 as a white solid in 91% ee. [α]D: +56.3 (EtOH, c=0.5). Analytical data for 9: IR (film) 1690.9, 1607.9, 1464.8, 1304.4, 1226.9 cm−1; 1H NMR (500 MHz, CDCl3) δ 7.99-7.89 (m, 5H), 7.63-7.54 (m, 4H), 7.13-7.09 (m, 2H), 5.68 (dd, J=13.1, 2.4 Hz, 1H), 3.22 (dd, J=16.8, 13.4 Hz, 1H), 3.00 (dd, J=16.8, 2.7 Hz, 1H); 13C NMR (125 MHz, CDCl3) δ 192.2, 161.8, 136.5, 136.3, 133.6, 133.4, 129.0, 128.4, 128.0, 127.3, 126.8 (x2), 125.6, 123.9, 121.9, 121.2, 118.4, 79.9, 44.9; LRMS (electrospray): Exact mass calcd. for C19H14O2 [M]+, 274.10. Found [M]+, 273.8.

Provenance & Evidence