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with EtOAc (3 ꢀ 100 ml). The resulting organic layer was successively
washed with H2O, a NaHCO3 solution and brine, dried over Na2SO4,
and concentrated in vacuo. The residual materials were chromato-
graphed over SiO2 (200 g), elution with hexane/EtOAc (10:1) gave
tosylate 4 (16 g, 41 mmol, 98%). 1H-NMR ꢀ: 0.02 (6H, s, Si(CH3)2),
0.83 (3H, d, J ¼ 6:5 Hz, CH3CH), 0.87 (9H, s, SiC(CH3)3), 1.32 (1H,
m), 1.47 (2H, m), 1.69 (2H, m), 2.45 (3H, s, CH3Ph), 3.59 (2H, m,
TBDMSOCH2), 4.07 (2H, m, TsOCH2), 7.34 (2H, d, J ¼ 8:5 Hz), 7.79
(2H, d, J ¼ 8:5 Hz). 13C-NMR ꢀ: ꢃ5:4 (ꢀ2), 18.3, 19.2, 21.6, 25.9
(ꢀ3), 26.2, 35.7, 39.4, 60.9, 68.9, 127.9 (ꢀ2), 129.8 (ꢀ2), 133.2,
144.6. IR ꢁmax cmꢃ1: 2929, 1604, 1475, 1363, 1178, 1097, 943, 837,
775, 663, 555.
J ¼ 6:5 Hz, CH3CH), 0.88 (3H, t, J ¼ 6:5 Hz, CH3CH2), ꢂ1:1 (2H,
m), ꢂ1:25 (22H, m), ꢂ1:35 (3H, m), 2.02 (2H, dt, J ¼ 7, 7 Hz,
CH2CH=C), 4.93 (1H, d, J ¼ 10:5 Hz, CH=CHH), 4.99 (1H, d,
J ¼ 17 Hz, CH=CHH), 5.82 (1H, ddt, J ¼ 17, 10.5, 6.5 Hz,
CH=CH2). IR ꢁmax cmꢃ1: 3078, 2924, 2846, 1641, 1464, 993, 908.
GC-MS: tR 12.74 min; m=z 266 (Mþ, 1%), 97 (100%), 57 (90%).
Ethyl 3-methyl-2-heptenoate (6). Triethyl phosphonoacetate (18.9 g,
72 mmol) dissolved in dry THF (40 ml) was treated with NaH (60%,
2.9 g, 72 mmol) while stirring at rt under Ar. The reaction mixture was
stirred for 20 min at rt, and EtOH (4.0 ml) was then added to quench
the remaining NaH. Next, 2-hexanone (6.0 g, 60 mmol) was added
dropwise and the mixture stirred for 1 h at rt and for an additional
30 min under reflux. The mixture was then cooled to rt, poured into a
saturated aqueous solution of NH4Cl (100 ml), and extracted with Et2O
(3 ꢀ 100 ml). After the usual work-up, the crude product was
chromatographed over SiO2 (300 g) with eluention by hexane and
hexane/EtOAc (10:1) to give a 1:1 mixture of (Z)-2-heptenoate and its
(E)-isomer (6; 9.5 g, 56 mmol, 93%). 1H-NMR (Z)-isomer ꢀ: 0.92 (3H,
t, J ¼ 7 Hz, CH3CH2CH2), 1.27 (3H, t, J ¼ 7 Hz, CH3CH2O), ꢂ1:4
(4H, m), 1.88 (3H, d, J ¼ 1:5 Hz, CH3C=C), 2.62 (2H, t, J ¼ 7:5 Hz,
CH2C=C), 4.13 (2H, q, J ¼ 7 Hz, CH3CH2O), 5.65 (1H, m, CH=C);
(E)-isomer ꢀ: 0.91 (3H, t, J ¼ 7 Hz, CH3CH2CH2), 1.28 (3H, t,
J ¼ 7 Hz, CH3CH2O), ꢂ1:4 (4H, m), 2.13 (2H, m, CH2C=C), 2.15
(3H, d, J ¼ 1:5 Hz, CH3C=C), 4.14 (2H, q, J ¼ 7 Hz, CH3CH2O),
5.66 (1H, m, CH=C). 13C-NMR ꢀ: 13.9, 14.0, 14.3, 14.4, 18.7, 22.3,
22.9, 25.2, 29.6, 30.4, 33.2, 40.7, 59.40, 59.44, 115.4, 116.0, 160.4,
160.8, 166.4, 166.9. IR ꢁmax cmꢃ1: 2908, 1739, 1649, 1461, 1367,
1149, 1039, 731. GC-MS: tR 8.20 min; m=z 170 (Mþ, 40%), 141
(46%), 125 (59%), 55 (100%).
3-Methyl-7-octen-1-ol (5). Tosylate 4 (15.5 g, 40 mmol) dissolved
in dry Et2O (60 ml) was treated with Li2CuCl4 (a 0.1 M THF solution,
1.0 ml) and allylmagnesium bromide (a 1.0 M Et2O solution, 44 ml)
while stirring at 0 ꢁC under Ar. The mixture was stirred at 0 ꢁC for 8 h
and poured into an H2SO4 solution (2.0 M, 200 ml), and the product
was extracted with Et2O (3 ꢀ 100 ml). After the usual work-up, the
crude product was chromatographed over SiO2 (200 g) with an eluent
of hexane/EtOAc (10:1) to give the TBDMS ether of 5 (8.5 g,
33 mmol, 83%). Next, to remove the protective group, the ether
dissolved in dry THF (10 ml) was treated with tetrabutylammonium
fluoride (TBAF, a 1.0 M THF solution, 40 ml) under Ar. The mixture
was stirred at rt for 3 h, poured into a saturated aqueous solution of
NH4Cl (100 ml), and extracted with Et2O (3 ꢀ 100 ml). After the usual
work-up, the crude product was chromatographed over SiO2 (200 g)
with an eluent of hexane/EtOAc (from 10:1 to 5:1) to give 5 (4.3 g,
30 mmol, 91%). 1H-NMR ꢀ: 0.90 (3H, d, J ¼ 6:5 Hz, CH3CH), ꢂ1:3
(4H, m), ꢂ1:6 (2H, m), 1.87 (1H, m), 2.04 (2H, dt, J ¼ 7, 7 Hz,
CH2CH=C), 3.68 (2H, m, CH2OH), 4.94 (1H, d, J ¼ 10:5 Hz,
CH=CHH), 5.00 (1H, d, J ¼ 17 Hz, CH=CHH), 5.81 (1H, ddt,
J ¼ 17, 10.5, 6.5 Hz, CH=CH2). 13C-NMR ꢀ: 19.6, 26.3, 29.4, 34.0,
36.5, 39.9, 61.2, 114.3, 139.1. IR ꢁmax cmꢃ1: 3365, 3078, 2929, 1641,
1460, 1057, 999, 910. GC-MS (relative intensity): tR 9.97 min; m=z 124
(½M ꢃ 18ꢄþ, 1%), 109 (11%), 81 (55%), 55 (100%).
3-Methyl-1-heptanol (7). A mixture of the heptenoate 6 (9.4 g,
55 mmol), Pd-C (10%, 250 mg), and MeOH (100 ml) was stirred under
H2 at rt for 1.5 h. After filtering off the catalyst, the solvent was
evaporated. The produced heptanoate dissolved in dry THF (20 ml)
was added dropwise to LiAlH4 (2.1 g, 55 mmol) suspended in dry THF
(30 ml) cooled in an ice bath. After stirring at rt for 1 h, an HCl solution
(1.0 M, 150 ml) was added dropwise to the reaction mixture, and the
crude product was extracted with Et2O (3 ꢀ 100 ml). After the usual
work-up, the product was chromatographed over SiO2 (200 g) with an
elution by hexane and hexane/EtOAc (from 10:1 to 2:1) to give 7
(6.8 g, 52 mmol, 95%). 1H-NMR ꢀ: 0.89 (3H, d, J ¼ 6:5 Hz, CH3CH),
0.89 (3H, t, J ¼ 6:5 Hz, CH3CH2), ꢂ1:3 (7H, m), ꢂ1:6 (2H, m), 3.69
(2H, m, CH2OH). 13C-NMR ꢀ: 14.1, 19.7, 23.0, 29.2, 29.5, 36.8, 40.0,
61.2. IR ꢁmax cmꢃ1: 3334, 2924, 1460, 1379, 1057. GC-MS: tR
8.23 min; m=z 112 (½M ꢃ 18ꢄþ, 2%), 97 (4%), 84 (67%), 55 (100%).
3-Methyl-7-octenyl tosylate (A1). In a similar manner to that for the
preparation of 4, alcohol 5 (4.3 g, 30 mmol) was tosylated with TsCl
(6.9 g, 36 mmol) and DMAP (200 mg). The crude product was
chromatographed over SiO2 (150 g) with an eluent of hexane/EtOAc
(10:1) to give A1 (8.4 g, 28 mmol, 93%). 1H-NMR ꢀ: 0.81 (3H, d,
J ¼ 6:5 Hz, CH3CH), 1.0–1.6 (6H, m), 1.66 (1H, m), 1.97 (2H, dt,
J ¼ 7, 7 Hz, CH2CH=C), 2.45 (3H, s, CH3Ph), 4.05 (2H, m, TsOCH2),
4.92 (1H, d, J ¼ 10:5 Hz, CH=CHH), 4.95 (1H, d, J ¼ 17 Hz,
CH=CHH), 5.76 (1H, ddt, J ¼ 17, 10.5, 6.5 Hz, CH=CH2), 7.34
(2H, d, J ¼ 8:5 Hz), 7.78 (2H, d, J ¼ 8:5 Hz). 13C-NMR ꢀ: 19.1, 21.6,
26.0, 29.0, 33.8, 35.6, 36.0, 69.0, 114.4, 127.8 (ꢀ2), 129.8 (ꢀ2), 133.1,
138.7, 144.6. IR ꢁmax cmꢃ1: 3074, 2927, 1639, 1599, 1460, 1361, 1176,
1097, 945, 891, 816, 665, 555.
3-Methylheptyl tosylate (B1). In a similar manner to that for the
preparation of 4, alcohol 7 (6.5 g, 50 mmol) was tosylated with TsCl
(11.4 g, 60 mmol) and DMAP (300 mg). The product was chromato-
graphed over SiO2 (200 g) with elution by hexane/EtOAc (10:1) to
give B1 (8.4 g, 46 mmol, 92%). 1H-NMR ꢀ: 0.80 (3H, d, J ¼ 6:5 Hz,
CH3CH), 0.86 (3H, t, J ¼ 6:5 Hz, CH3CH2), 1.0–1.3 (6H, m), ꢂ1:4
(1H, m), ꢂ1:5 (1H, m), 1.65 (1H, m), 2.45 (3H, s, CH3Ph), 4.06 (2H,
m, TsOCH2), 7.35 (2H, d, J ¼ 8:5 Hz), 7.79 (2H, d, J ¼ 8:5 Hz). 13C-
NMR ꢀ: 14.1, 19.2, 21.6, 22.8, 29.0, 29.1, 35.7, 36.3, 69.1, 127.9 (ꢀ2),
129.8 (ꢀ2), 133.2, 144.6. IR ꢁmax cmꢃ1: 2927, 1599, 1466, 1362, 1176,
945, 887, 816, 665, 555.
8-Iodo-6-methyl-1-octene (A2). NaI (4.5 g, 30 mmol) was added to a
solution of tosylate A1 (5.7 g, 20 mmol) in dimethylformamide (DMF,
25 ml) at rt, and the mixture was stirred at 100 ꢁC for 2 h. After cooling
to rt, the mixture was poured into water (400 ml) and extracted with
hexane (3 ꢀ 100 ml). The crude product was chromatographed over
SiO2 (100 g) after the usual work-up. Elution with hexane gave A2
(4.5 g, 18 mmol, 90%). 1H-NMR ꢀ: 0.88 (3H, d, J ¼ 6:5 Hz, CH3CH),
ꢂ1:3 (4H, m), ꢂ1:55 (1H, m), 1.65 (1H, m), 1.87 (1H, m), 2.04 (2H,
dt, J ¼ 7, 7 Hz, CH2CH=C), 3.17 (1H, ddd, J ¼ 9:5, 8, 8 Hz, CHHI),
3.25 (1H, ddd, J ¼ 9:5, 9.5, 5.5 Hz, CHHI), 4.95 (1H, d, J ¼ 10:5 Hz,
CH=CHH), 5.00 (1H, d, J ¼ 17 Hz, CH=CHH), 5.81 (1H, ddt,
J ¼ 17, 10.5, 6.5 Hz, CH=CH2). 13C-NMR ꢀ: 5.2, 18.7, 26.1, 33.7,
33.9, 35.7, 40.9, 114.4, 138.9. IR ꢁmax cmꢃ1: 3076, 2927, 1639, 1460,
1178, 995, 910, 606. GC-MS: tR 9.80 min; m=z 252 (Mþ, 1%), 155
(6%), 97 (13%), 55 (100%).
1-Iodo-3-methylheptane (B2). In a similar manner to that for the
iodination of A1, tosylate B1 (5.7 g, 20 mmol) was converted to B2
(4.3 g, 18 mmol, 90%). 1H-NMR ꢀ: 0.87 (3H, d, J ¼ 6:5 Hz, CH3CH),
0.89 (3H, t, J ¼ 6:5 Hz, CH3CH2), 1.1–1.35 (6H, m), ꢂ1:55 (1H, m),
1.64 (1H, m, CHHCH2I), 1.87 (1H, m, CHHCH2I), 3.17 (1H, ddd,
J ¼ 9:5, 8, 8 Hz, CHHI), 3.25 (1H, ddd, J ¼ 9:5, 9.5, 5.5 Hz, CHHI).
13C-NMR ꢀ: 5.3, 14.1, 18.8, 22.9, 29.0, 33.9, 35.9, 41.0. IR ꢁmax cmꢃ1
:
2925, 1464, 1379, 1214, 1178, 606. GC-MS: tR 7.96 min; m=z 240
(Mþ, 2%), 155 (7%), 127 (3%), 113 (20%), 57 (100%).
6-Methyl-1-octadecene (1). In a similar manner to that for the
alkylation of 4, tosylate A1 (3.0 g, 10 mmol) was coupled with
decylmagnesium bromide (a 1.0 M Et2O solution, 14 ml) by using
Li2CuCl4 (a 0.1 M THF solution, 1.0 ml) as a catalyst. The crude
product was chromatographed over SiO2 (150 g) with an eluent of
hexane to give 1 (2.6 g, 9.8 mmol, 98%). 1H-NMR ꢀ: 0.85 (3H, d,
14-Methyl-1-octadecene (2). To dry THF (30 ml) containing Mg
turnings (0.97 g, 40 mmol), 11-bromo-1-undecene (4.7 g, 20 mmol) in
dry THF (4 ml) was added while stirring at 0 ꢁC under Ar. After stirring
at 0 ꢁC for 1 h, the mixture was warmed to rt. The produced Grignard