Compound 3e

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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.

1e was fluorinated following general procedure A described for compound 3a, using DCM as solvent. A mixture of 3e/1e was isolated by preparative TLC (16.1 mg, 1/0.42 ratio, 52% yield). Pure analytical sample was isolated by additional preparative TLC using hexanes/ethyl acetate as eluent (92% ee). The ee value was determined by HPLC analysis on a Chiralcel AS-H column (2% isopropanol in hexanes, 0.8 mL/min) with retention time of 14.9 min (minor) and 16.6 min (major). Absolute stereochemistry was assigned based on the X-ray crystallographic data of compound 5a. ¹H NMR (600 MHz, CDCl₃): δ 10.17 (s, 1H), 8.42 (s, 1H), 8.24 – 8.18 (m, 1H), 7.84 (d, J = 8.1 Hz, 1H), 6.49 (dq, J = 48.5, 6.3 Hz, 1H), 3.60 (sp, J = 7.0 Hz, 1H), 1.65 (dd, J = 24.1, 6.3 Hz, 3H), 1.26 (d, J = 7.4 Hz, 6H). ¹³C NMR (150 MHz, CDCl₃): δ 202.75, 192.29, 148.56 (d, J = 19.6 Hz), 135.92, 134.22, 133.60, 132.06 (d, J = 3.8 Hz), 125.96 (d, J = 14.0 Hz), 88.07 (d, J = 169.3 Hz), 35.61, 23.13 (d, J = 24.6 Hz), 19.00, 18.98. ¹⁹F NMR (376 MHz, CDCl₃): δ –175.08. HRMS (ESI-TOF): m/z calculated for C₁₃H₁₆FO₂⁺ [M+H]⁺ 223.1129, found 223.1133.