CHEM01200604012 Dibakar Goswami - Homi Bhabha National ...

Non-2-yn-1-ol 76. To a stirred solution of Fe (NO 3 ) 2 (0.4g) in liquid ammonia (700 mL)
Li-metal (3.9g, 0.561 mol) in small pieces in 30 min. Freshly distilled propargyl alcohol 75
(15.0 g, 0.27 mol) was added to the suspension dropwise over 1 h. After stirring for 30
min, 1-bromohexane (53.1 g, 0.32 mol) was added very slowly into it and stirring was
continued for additional 6 h. The mixture was slowly brought to room temperature,
allowing the ammonia to evaporate. The mixture was treated with aqueous saturated
NH 4 Cl (200 mL) and extracted with ethyl acetate (300 mL). The combined organic extracts
were dried, concentrated in vacuo, and the residue chromatographed (silica gel, 5-15%
EtOAc/hexane) to afford the compound 76. Yield: 23.0 g (61%); colourless oil; IR: 3347,
2225, 1013 cm -1 ; 1 H NMR: δ 0.77 (t, J = 6.8 Hz, 3H), 1.10-1.38 (m, 8H), 2.04-2.12 (m,
2H), 3.37 (broad s, 1H), 4.01-4.13 (m, 2H); 13 C NMR: δ 13.9, 18.6, 22.4, 28.4, 28.5, 31.3,
50.7, 78.3, 85.8. Anal. Calcd. for C 9 H 16 O: C, 77.09; H, 11.5%. Found, C, 77.25; H,
11.62%.
(E)-Non-2-en-1-ol 77a : To a suspension of LiAlH 4 (5.32 g, 0.14 mol) in dry THF (200
mL) was added a solution of 76 (10.16 g, 72.5 mmol) in dry THF (150 mL). The reaction
mixture was stirred at 45 °C for 30 mins and gradually brought to 0 °C. The excess hydride
was decomposed with aqueous saturated Na 2 SO 4 solution, extracted with Et 2 O (300 mL).
The combined ethereal extracts were dried, concentrated under reduced pressure, and the
residue was purified by flash chromatography (20% EtOAc/hexane) to give the transallylic
alcohol 77a. Yield: 7.82 g (76%); colourless oil; IR: 3340, 1203 cm -1 ; 1 H NMR: δ
0.80 (t, J = 6.6 Hz, 3H), 1.17-1.23 (m, 8H), 1.50 (broad s, 1H), 1.94-1.99 (m, 1H), 2.12-
2.23 (m, 1H), 4.00-4.12 (m, 2H), 5.48-5.71 (m, 2H); 13 C NMR: δ 13.9, 22.5, 28.8, 29.0,
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