Compound 3f

View in PubChem | MDL Molfile | Chemdraw file

Compound data: HPLC

Compound data: 1H NMR

Compound data: 13C NMR

Compound data: 19F NMR

Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

1f was fluorinated following general procedure A described for compound 3a, using benzene as solvent. A mixture of 3f/1f was isolated by preparative TLC (12.4 mg, 1/0.10 ratio, 58% yield). Pure analytical sample was isolated by additional preparative TLC using hexanes/THF as eluent (90% ee). The ee value was determined by HPLC analysis on a Chiralcel AS-H column (3% isopropanol in hexanes, 0.5 mL/min) with retention time of 27.7 min (minor) and 32.4 min (major). Absolute stereochemistry was assigned based on the X-ray crystallographic data of compound 5a. ¹H NMR (600 MHz, CDCl₃): δ 10.18 (s, 1H), 8.70 (dd, J = 2.3, 1.2 Hz, 1H), 8.50 (dd, J = 8.6, 2.4 Hz, 1H), 7.95 (d, J = 8.6 Hz, 1H), 6.50 (dq, J = 48.5, 6.4 Hz, 1H), 1.66 (dd, J = 24.1, 6.3 Hz, 3H). ¹³C NMR (150 MHz, CDCl₃): δ 190.53l, 150.73 (d, J = 19.7 Hz), 147.67, 132.54 (d, J = 3.7 Hz), 128.62, 128.45 (d, J = 1.7 Hz), 127.18 (d, J = 14.7 Hz), 87.77 (d, J = 171.2 Hz), 23.06 (d, J = 24.5 Hz). ¹⁹F NMR (376 MHz, CDCl₃): δ –175.06. HRMS (ESI-TOF): m/z calculated for C₉H₉FNO₃⁺ [M+H]⁺ 198.0561, found 198.0556.