Methyl vinyl ketone → 3,6-Dimethylhepta-1,6-dien-4-yn-3-ol

Participants

Reaction Steps

The title compound was prepared according to the general method above by using 2-methylbut-1-en-3-yne (1.725 g, 26.09 mmol), nBuLi (18.0 mL, 28.8 mmol) and but-3-en-2-one (2.194 g, 31.30 mmol). Crude product was purified by flash chromatography (2.229 g, 16.37 mmol, 62.7%): Rf 0.28 (hexanes/Et2O, 4:1); 1H NMR (300 MHz, CDCl3) δ 6.00 (dd, J=17.1, 10.2 Hz, 1H, H-2), 5.49 (dd, J=17.1, 0.7 Hz, 1H, H-1trans), 5.25-5.32 (m, 1H, H-7), 5.18-5.25 (m, 1H, H-7), 5.11 (dd, J=10.2, 0.7 Hz, 1H, H-1 cis), 2.24 (s, 1H, —OH), 1.88 (as, 3H, H-8), 1.56 (s, 3H, H-9); 13C NMR (300 MHz, CDCl3) δ 142.0 (C-2), 126.2 (C-6), 122.1 (C-7), 113.5 (C-1), 89.9 (C-4/5), 85.9 (C-4/5), 68.5 (C-3), 29.9 (C-9), 23.4 (C-8); HRMS calcd for C9H13O (M+H)+ 137.0966. found 137.0984.

Provenance & Evidence