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T. Shindo et al.
PAPER
Elution with hexane–Et2O (90:1) afforded the desired products (90–
92% yields).
(E)-3,7-Dimethyl-2,6-octadiene-1-ol (15a)
Colorless oil.
1H NMR (400 MHz, CDCl3): d = 1.61 (s, 3 H), 1.68 (s, 6 H), 2.02–
2.14 (m, 4 H), 4.16 (d, J = 6.8 Hz, 2 H), 5.08–5.12 (tt, J = 1.6, 6.8
Hz, 1 H), 5.40–5.44 (tq, J = 6.8, 1.6 Hz, 1 H). Its NMR spectrum
was identical with that of an authentic specimen (Junsei Chemical
Co. Cat. No. 29235-0435).
(E)-3,7-Dimethyl-2,6-octadiene-1-ol MXM Ether (15c)
Colorless oil.
IR (film): 2915, 1591, 1469, 1444, 1377, 1164, 1061, 991, 827, 769
cm–1.
1H NMR (270 MHz, CDCl3): d = 1.60 (s, 3 H), 1.68 (s, 6 H), 2.01–
2.14 (m, 4 H), 2.39 (s, 6 H), 4.05 (d, J = 6.8 Hz, 2 H), 4.50 (s, 2 H),
5.07–5.13 (br t, J = 6.8 Hz, 1 H), 5.39–5.45 (tq, J = 1.4, 6.8 Hz, 1
H), 7.00 (d, J = 6.2 Hz, 2 H), 7.06–7.10 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 16.5, 17.7, 19.6, 25.7, 26.4, 39.6,
66.2, 66.8, 120.9, 123.9, 127.8, 128.0, 131.5, 134.3, 137.8, 140.3.
(E)-2-Tetradecen-4-ol (16a)26
Colorless oil.
1H NMR (400 MHz, CDCl3): d = 0.88 (t, J = 6.8 Hz, 3 H), 1.26 (m,
18 H), 1.71 (dd, J = 1.6, 6.8 Hz, 3 H), 4.00–4.05 (dt, J = 6.8, 6.8 Hz,
1 H), 5.45–5.51 (ddq, J = 6.8, 15.4, 1.6 Hz, 1 H), 5.61–5.70 (dq, J =
15.4, 6.8 Hz, 1 H). Based on the chemical shifts of allylic methine
protons (E and Z),41the determination of the ratio (E:Z) was per-
formed by comparing the area of signals in 1H NMR : (E)-isomer,
d = 4.00–4.05 (dt); (Z)-isomer, d = 4.44–4.49 (dt).
Anal. Calcd for C19H28O: C, 83.77; H, 10.36. Found: C, 83.68; H,
10.21.
(E)-2-Tetradecen-4-ol MXM Ether (16c)
Colorless oil.
IR (film): 2923, 1467, 1070, 968, 767 cm–1.
(E)-2-Tridecen-1-ol (21)
Colorless oil.
1H NMR (400 MHz, CDCl3): d = 0.88 (t, J = 6.8 Hz, 3 H) 1.26–1.37
(m, 16 H), 2.01–2.06 (q, J = 6.8 Hz, 2 H), 4.08 (d, J = 5.6 Hz, 2 H),
5.58–5.73 (m, 2 H). Its NMR spectra were identical with those re-
ported previously.42 The determination of the ratio (E:Z = 26:1) was
based on the area of signals in 1H NMR: (E)-isomer. d = 5.58–5.73
(m); (Z)-isomer, d = 5.35–5.41 (m).
1H NMR (270 MHz, CDCl3): d = 0.89 (t, J = 6.8 Hz, 3 H), 1.25 (m,
18 H), 1.77 (dd, J = 1.6, 6.8 Hz, 3 H), 2.37 (s, 6 H), 3.60–3.68 (dt,
J = 6.8, 7.2 Hz, 1 H), 4.26 (d, J = 10.3 Hz, 1 H), 4.56 (d, J = 10.3
Hz, 1 H), 5.36-5.45 (ddq, J = 6.8, 15.2, 1.6 Hz, 1 H), 5.63–5.76 (dq,
J = 15.2, 6.8 Hz, 1 H), 6.98–7.09 (m, 3 H).
13C NMR (68 MHz, CDCl3): d = 14.2, 17.8, 19.6, 22.8, 25.8, 29.4,
29.6, 29.7, 32.0, 35.9, 64.4, 80.9, 127.6, 128.0, 128.2, 132.4, 134.6,
137.7.
Selective Hydrogenolysis: Comparative Study between 22b and
22c
Anal. Calcd for C23H38O: C, 83.57; H, 11.59. Found: C, 83.50; H,
11.55.
A mixture of Bn ether and MXM ether (47:53 molar ratio, 50 mg,
total 0.14 mmol) was dissolved in EtOH (1.7 mL) and then 10% Pd
on carbon (2.6 mg) was added. The mixture was stirred under H2 at
atmospheric pressure at r.t. for 6 min. The reaction mixture was fil-
tered through a pad of Celite, and the residual solid was washed
with EtOAc. The combined filtrate was concentrated in vacuo. The
residue was purified by silica gel column chromatography (2 g).
Elution with hexane–EtOAC (5:1) afforded 1-hexadecanol (13.7
mg, 39%) and resulted in the recovery of MXM ether (22c, 49%)
and Bn ether (22b, 4.6%). The determination of the yield (MXM
ether and Bn ether) was performed by comparing the area of signals
in 1H NMR spectra (400 MHz, CD3OD): MXM ether 22c: d = 6.99–
7.06 (m); Bn ether 22b: d = 7.32 (m).
(Z)-3,7-Dimethyl-2,6-octadiene-1-ol MXM Ether (17b)
Colorless oil.
IR (film): 2916, 1668, 1590, 1469, 1241, 1197, 1060, 769, 744, 688
cm–1.
1H NMR (400 MHz, CDCl3): d = 1.60 (s, 3 H), 1.68 (s, 3 H), 1.75
(d, J = 0.8 Hz, 3 H), 2.07–2.11 (m, 4 H), 2.39 (s, 6 H), 4.03 (d, J =
6.8 Hz, 2 H), 4.50 (s, 2 H), 5.09–5.10 (m, 1 H), 5.40–5.43 (br t, J =
6.8 Hz, 1 H), 7.00 (d, J = 7.6 Hz, 2 H), 7.06–7.10 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 17.7, 19.7, 23.5, 25.8, 26.8, 32.2,
66.3, 66.6, 122.0, 123.8, 127.9, 128.0, 131.8, 134.3, 137.8, 140.4.
Catalytic Hydrogenation of Allylic Ethers; General Procedure
The hydrogenolysis of 16b and 16c was carried out in a convention-
al manner as described above. The yields of the products including
4-tetradecanol 23a43 from the either substrate are summarized in
Table 4. The characterizations of saturated ethers are as follows.
Anal. Calcd for C19H28O: C, 83.77; H, 10.36. Found: C, 83.85; H,
10.34.
2-Tridecyn-1-ol MXM Ether (20a)
Colorless oil.
IR (film): 2925, 2279, 2220, 1468, 1352, 1070, 769 cm–1.
4-Benzyloxytetradecane (23b)
1H NMR (270 MHz, CDCl3): d = 0.88 (t, J = 6.8 Hz, 3 H), 1.23–1.40
(m, 14 H), 1.51–1.55 (m, 2 H), 2.21–2.28 (tt, J = 2.2, 7.0 Hz, 2 H),
2.41 (s, 6 H), 4.17 (t, J = 2.2 Hz, 2 H), 4.61 (s, 2 H), 7.00 (d, J = 8.1
Hz, 2 H), 7.07–7.12 (m, 1 H).
13C NMR (100 MHz, CDCl3): d = 14.2, 18.9, 19.6, 22.7, 28.7, 29.0,
29.2, 29.4, 29.5, 29.6, 31.9, 58.0, 65.5, 76.2, 87.1, 128.0, 128.1,
133.7, 138.0.
Colorless oil.
IR (film): 2925, 1456, 1070, 730, 696 cm–1.
1H NMR (400 MHz, CDCl3): d = 0.88–0.93 (m, 6 H), 1.26–1.55 (m,
22 H), 3.34-3.40 (tt, J = 6.0, 6.0 Hz, 1 H), 4.50 (s, 2 H), 7.26–7.34
(m, 5 H).
13C NMR (100 MHz, CDCl3): d = 14.2, 14.4, 18.7, 22.8, 25.4, 29.4,
29.68, 29.71, 29.90, 29.91, 32.0, 33.9, 36.2, 70.7, 78.9, 127.3,
127.7, 128.2, 139.2.
Anal. Calcd for C22H34O: C, 84.02; H, 10.90. Found: C, 83.95; H,
10.85.
MS (EI): m/z = 305 [M + H+], 91 [C7H7 ].
+
Synthesis of Allylic Alcohols and Deprotection Reaction Using
Li-Ethylenediamine–THF System; General Procedure
The reaction was carried out essentially in the same manner as de-
scribed for the cleavage of aryl methyl ethers except for 20a (at –78
°C to 0 °C). The yields of the products are listed in Table 4.
4-(2¢,6¢-Dimethylbenzyl)oxytetradecane (23c)
Colorless oil.
IR (film) 2925, 1466, 1377, 1132, 1055, 768 cm–1.
Synthesis 2004, No. 5, 692–700 © Thieme Stuttgart · New York