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K. Mori, C.Y. Yang / Tetrahedron 72 (2016) 4593e4607
891 (m), 721 (m), dH (CDCl3): 0.87 (3H, d, J 7.2), 0.88 (3H, t, J 7.2),
1.08e1.15 (2H, m), 1.15e1.35 (40H, br, peak at 1.26), 1.35e1.45 (2H,
m), 2.05e2.20 (2H, m), 4.91 (1H, d, J 11), 5.06 (1H, d, J 17), 5.48 (1H,
t, J 7), 6.36 (1H, dd, J 11, 17); GCeMS (same conditions as those used
for 24): tR 19.62 min (93.0%); MS (70 eV, EI): m/z: 404 (24) [Mþ], 389
(4), 375 (16), 334 (6), 137 (10), 123 (100), 109 (20), 95 (72), 81 (69),
80 (65), 69 (26), 57 (39), 55 (32), 43 (48), 41 (29). HRMS calcd for
(93.3%); MS (70 eV, EI): m/z: 450 (<1) [Mþ], 435 (4), 351 (14), 280
(7), 197 (15), 183 (3), 169 (5), 155 (5), 141 (7), 126 (16), 113 (14), 99
(16), 97 (16), 85 (59), 71 (79), 57 (100), 43 (65), 41 (27). HRMS calcd
for C32H66: 450.5165, found; 450.5154.
4.25. 2,6-Dimethyl-2-tridecene (41)
C
29H56: 404.4382, found: 404.4377.
In the same manner as described for 10 in 4.2, 9 (12.5 g,
40 mmol) was treated with n-C5H11MgBr prepared from n-C5H11Br
(8.8 g, 80 mmol) and Mg (2.0 g, 83 mmol) in THF (50 mL) in the
presence of Li2CuCl4 in THF (0.1 M, 3 mL, 0.3 mmol) to give 9.02 g of
crude 40 as a colorless oil, nmax (film): 2959 (s), 2925 (s), 2855 (s),
1459 (m), 1377 (m), 1057 (w), 984 (w), 828 (w), 723 (w). The oily 41
was used in the next step without further purification.
4.22. (6EZ,8E)-8,12-Dimethyl-6,8-triacontadiene (40)
In the same manner as described for 39 in 4.21, a Wittig reagent
was prepared form Ph3P[(CH2)5Me]Br (5.1 g, 12 mmol) and n-BuLi
(1.6 M, 8 mL,12.8 mmol) in dry THF (30 mL) under argon. A solution
of 38 (2.4 g, 6.4 mmol) in dry THF (10 mL) was added to the cooled
Wittig reagent. Subsequent work-up including SiO2 (50 g) chro-
matography gave 40 (1.43 g, 51%) as a colorless oil, n2D6¼1.4680; nmax
(film): 2956 (s), 2925 (s), 2852 (s), 1650 (w), 1465 (m), 1377 (m),
1305 (w), 962 (m), 721 (m); dH (CDCl3): 0.82e0.94 (9H, m),
1.14e1.45 (43H, br, peak at 1.26), 1.72 (1.8H, s), 1.76 (1.2H, s),
1.94e2.16 (3.4H, m), 2.18e2.26 (0.6H, m), 5.22e5.42 (1.5H, m),
5.50e5.60 (0.5H, m), 5.75e5.82 (0.5H, d, J 8) 6.02e6.06 (0.5H, d, J
16); dC (CDCl3): 12.41, 14.08, 14.13, 16.68, 19.61, 22.60, 22.72, 25.66,
25.71, 27.05, 27.09, 29.40, 29.47, 29.73, 30.05, 31.56, 31.60, 31.96,
32.49, 32.89, 36.88, 36.94, 36.98, 37.01, 127.53, 129.63, 129.91,
130.87, 132.39, 132.84, 132.29, 134.78; GCeMS (same conditions as
those used for 24): tR 20.97 (28.0%), 21.63 min (66.8%) (total 94.8%.
These are the E/Z-isomers); MS of 40 with tR¼20.97 min (70 eV, EI):
m/z: 446 (55) [Mþ], 347 (11), 193 (18), 165 (18), 151 (13), 137 (14),
123 (34), 109 (38), 95 (68), 81 (100), 57 (61), 43 (75); MS of 40 with
tR¼21.63 min (70 eV, EI): m/z: 446 (22) [Mþ], 431 (4), 375 (3), 361
(14), 347 (9), 320 (4), 306 (7), 193 (29), 165 (32), 138 (26), 109 (35),
95 (73), 81 (100), 57 (53), 43 (66). HRMS calcd for C32H62: 446.4852,
found: 446.4835.
4.26. 2,6-Dimethyl-2-octadecene (42)
In the same manner as described for 10 in 4.2, 9 (12.5 g,
40 mmol) was treated with n-C10H21MgBr prepared from n-
C10H21Br (15.5 g, 70 mmol) and Mg (1.8 g, 75 mmol) in THF (65 mL)
in the presence of Li2CuCl4 in THF (0.1 M, 3 mL, 0.3 mmol) to give
17.2 g of crude 42 as a colorless oil, nmax (film): 2597 (s), 2925 (s),
2854 (s), 1466 (m), 1377 (m), 1058 (w), 826 (m), 721 (w). The oily 42
was used in the next step without further purification.
4.27. 2,6-Dimethyltridecane-2,3-diol (43)
In the same manner as described for 11 in 4.3, crude 41 (9.02 g,
40 mmol) in t-BuOH (80 mL), acetone (180 mL) and H2O (44 mL)
was oxidized with a solution of OsO4 (1% in t-BuOH, 15 mL, 150 mg)
and N-methylmorpholine N-oxide (50% NMO in H2O, 30 g,
120 mmol). The mixture was stirred for 3 d at room temperature,
and worked up to give 6.93 g (71%) of 43 as a slightly tan-colored
oil, n2D5¼1.4490; nmax (film): 3405 (br. m), 2956 (s), 2925 (s), 2855
(s), 1465 (m), 1378 (m), 1165 (m), 1073 (m); dH (CDCl3): 0.84e0.94
(6H, m), 1.06e1.20 (2H, m), 1.16 (3H, s), 1.21 (3H, s), 1.20e1.65 (15H,
m, peak at 1.26) 2.10e2.22 (1H, br), 2.25e2.36 (1H, br), 3.28e3.36
(1H, m). HRMS calcd for C15H32O2: 244.2402, found: 244.2405.
4.23. 3,7-Dimethylheptacosane (3)
10% PdeC (150 mg) was added to a solution of 39 (867 mg,
2.1 mmol) in hexane (8 mL). The suspension was stirred vigorously
under H2 (balloon) for 1.5 h at room temperature. Then the mixture
was transferred to the top of a column of SiO2 (5 g) in hexane.
Elution with hexane gave 3 (867 mg, 99%) as a colorless oil,
n2D4¼1.4510; nmax (film): 2957 (s), 2925 (s), 2852 (s), 1464 (m), 1377
(m), 1304 (w), 1153 (w), 1077 (w), 1011 (w), 967 (w), 890 (w), 769
(w), 721 (m); dH (CDCl3): 0.82e0.90 (12H, m), 1.00e1.16 (4H, m),
1.16e1.44 (44H, br, peak at 1.32); dC (CDCl3): 11.42, 14.13, 19.23,
19.29, 19.72, 19.78, 22.73, 23.08, 24.54, 27.14, 29.41, 29.51, 29.61,
29.74, 30.08, 31.63, 31.98, 32.80, 32.83, 36.84, 37.00, 37.04, 37.12,
37.21, 37.45, 37.50; GCeMS (same conditions as those used for 24):
tR 19.15 min (93.9%); MS (70 eV, EI): m/z: 407 (<1) [(MꢂH)þ], 393
(3), 379 (9), 309 (13), 308 (11), 280 (3), 253 (1), 239 (2), 225 (2), 211
(3), 197 (3), 183 (3), 169 (4), 155 (4), 141 (6), 127 (28), 113 (11), 99
(14), 97 (21), 85 (57), 71 (80), 57 (100), 43 (59), 41 (31). HRMS calcd
for C29H60: 408.4695, found: 408.4694.
4.28. 2,6-Dimethyloctadecane-2,3-diol (44)
In the same manner as described for 43 in 4.27, 42 (17.2 g,
40 mmol) was oxidized with OsO4 and NMO to give 12.5 g (99%) of
44, a portion of which crystallized as small needles, mp 47e48 ꢁC;
nmax, (Nujol): 3410 (br s), 1331 (m), 1085 (s), 966 (m), 719 (m); dH
(CDCl3): 0.85e0.92 (6H, m), 1.08e1.18 (2H, m), 1.16 (3H, s), 1.21 (3H,
s), 1.20e1.46 (25H, m, peak at 1.26), 2.03 (1H, s), 2.14e2.20 (1H, m),
3.30e3.70 (1H, m). HRMS calcd for C20H42O2: 314.3185, found:
314.3188.
4.29. 4-Methylundecanal (45)
In the same manner as described for 12 in 4.4, 43 (6.93 g,
28.4 mmol) was treated with HIO4$2H2O (6.84 g, 30 mmol) in THF
(65 mL) to give 4.37 g (84%) of 45 after SiO2 (50 g) chromatography
and elution with hexane/EtOAc (30:1). The aldehyde 45 was ob-
tained as a colorless oil, nD24¼1.4430; nmax (film): 2957 (s), 2926 (s),
2855 (s), 2713 (m), 1728 (s), 1465 (m), 1379 (m), 1037 (w), 723 (w);
dH (CDCl3): 0.87 (3H, d, J 6), 0.88 (3H, t, J 6.4), 1.08e1.18 (1H, m),
1.20e1.36 (11H, br, peak at 1.26), 1.38e1.49 (2H, m), 1.60e1.72 (1H,
m), 2.34e2.50 (2H, m), 9.77 (1H, t J 2); GCeMS (same conditions as
those used for 12): tR 9.75 min (93.4%); MS (70 eV, EI): m/z: 183
(<1) [(M-1)þ], 140 (20), 125 (22), 112 (23), 95 (29), 85 (54), 82 (36),
71 (35), 69 (46), 57 (91), 56 (100), 43 (59), 41 (64). HRMS calcd for
4.24. 8,12-Dimethyltriacontane (4)
In the same manner as described for 3 in 4.23, 40 (1.32 g,
3.5 mmol) in hexane (10 mL) was hydrogenated over 10% PdeC
(150 mg) to give 4 (1.28 g, 96%) as a colorless oil, n2D7¼1.4514; nmax
(film): 2925 (s), 2849 (s), 1465 (s), 1377 (m), 1304 (w), 1154 (w),
1077 (w), 934 (w), 891 (w), 721 (m), dH (CDCl3): 0.84 (6H, d, J 6.4),
0.88 (6H, t, J 6.8), 1.02e1.12 (4H, m), 1.20e1.40 (50H, br, peak at
1.26); dC (CDCl3): 14.13,19.72,19.79, 22.73, 24.50, 27.14, 29.41, 29.45,
29.71, 29.74, 30.08, 31.97, 32.79, 32.81, 37.10, 37.20, 37.42, 37.48;
GCeMS (same conditions as those used for 24): tR 20.71 min
C12H24O: 184.1827, found: 184.1827.