3-(2-Chlorophenyl)propanal → HCID 86644264, compound

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Prepared according to the general procedure from 2-chloro-hydrocinnamaldehyde and (E)-ethyl 2-oxo-4-p-tolylbut-3-enoate using 2 mol % 1 as the catalyst in 74% yield as a single diastereomer (colorless oil). [α]D2 (c 1.02, CHCl3)=+310.3; 1H NMR (400 MHz, CDCl3) δ 7.32-7.24 (m, 3H), 7.16-7.07 (m, 4H), 6.93-6.91 (m, 2H), 6.65 (d, 1H, J=6.8 Hz), 4.30 (q, 1H, J=7.1 Hz), 3.58 (t, 1H, J=6.7 Hz), 3.29-3.23 (m, 2H), 2.41 (dd, 1H, J=15.8, 10.9 Hz), 2.35 (s, 3H), 1.33 (t, 3H, J=7.1 Hz); 13C NMR (100 MHz, CDCl3) δ 168.9, 160.7, 142.1, 138.3, 132.8, 130.0, 129.1, 128.8, 128.4, 126.9, 118.9, 62.1, 45.0, 40.3, 32.1, 21.3, 14.3; IR (thin film) ν 3062, 3027, 2982, 2925, 1776, 1732, 1316, 1267, 1106 cm−1; HRMS (ESI) calcd for C22H22O4 [M+Na]+ 373.1410, found 373.1409; 97% ee (4S,5S)-isomer as determined by HPLC (AD-H, 9:1 hexanes/i-PrOH), tr (4S,5S)=21.7 min, tr (4R,5R)=13.4 min.

Provenance & Evidence