Cornforth reagent → (E)-Hexadec-2-enal

Participants

Reaction Steps

To a stirred suspension of 60.6 g (0.161 mol) pyridinium dichromate in 100 mL of dichloromethane was added 25.7 g (0.107 mol) of trans-2-hexadecenol. After 4 h at 25° C., the mixture was filtered (through Celite diatomaceous earth) and the resulting brown solution refiltered through Florisil, an activated magnesium silicate in the form of hard, porous, stable, white granules that are free from dusting sold by Floridin Co. The colorless solution obtained was concentrated in vacuo to 21.8 g (86%) of a white solid. Distillation (90-100° C./0.40-0.45 torr) provided 19.1 g (75%) of pure trans-2-hexadecenal as a white waxy solid. IR (thin film as melt) 2920, 2850, 1695, 1465, 975 cm-1 ; 1H NMR (CDCl3, 300 MHz) δ 9.53 (d, 1, J=6.7 Hz, CHO), 6.88 (overlapping dt. 1, J=15.7, 6.7 Hz, OHCCH=), 1.53 (m, 2CH2CH3), 1.1-1.2 (m, 20, CH2CH2CH2), 0.90 (t, 3, J=7 Hz, CH2CH3). Rf (15% ethyl acetate:hexanes): trans-2-hexadecenol, 0.19 trans-2-hexadecenal, 0.44. MS(FD) m/e 238 (M+).

Provenance & Evidence