Synthesis of (S)-2-Methylpent-3-yl 3,13-Dimethylpentadecanoates
over SiO2 (50 g) impregnated with AgNO3 (10%). Elution with
(m, 2 H, Ph), 7.17 (m, 1 H, Ph), 7.26 (m, 2 H, Ph) ppm. 13C NMR
(75 MHz, CDCl3, 25 °C): δ = 7.4, 19.4, 27.0, 28.5, 29.4, 29.7, 30.5,
33.5, 35.0, 36.6, 43.7, 125.5, 128.0 (ϫ2), 129.1 (ϫ2), 141.6 ppm.
GC–MS (EI, 70 eV): tR = 30.24 min [m/z (%) = 358 (23) [M]+, 343
(1) [M – 15]+, 267 (3), 253 (1), 239 (1), 225 (3), 211 (7), 197 (7),
hexane/toluene (14:1) afforded (R)-11 (3.59 g, 16 mmol, 98%) as an
oil. [α]2D3 = +11.18 (c = 1.43, CHCl ). IR (neat): ν = 3026 (m), 2925
˜
3
(s), 2854 (s), 1641 (m, C=C), 1454 (s), 908 (s), 698 (s) cm–1. 1H
NMR (300 MHz, CDCl3, 25 °C): δ = 0.83 (d, J = 6.6 Hz, 3 H,
CH3CH), 1.1–1.4 (m, 10 H), 1.70 (m, 1 H, CH3CH), 2.03 (dt, J = 183 (13), 169 (11), 155 (11), 133 (6), 119 (11), 105 (18), 91 (100),
7.0, 7.0 Hz, 2 H, CH2CH=CH2), 2.34 (dd, J = 13.3, 8.2 Hz, 1 H,
CHHPh), 2.63 (dd, J = 13.3, 6.0 Hz, 1 H, CHHPh), 4.92 (d, J =
10.3 Hz, 1 H, CH=CHH), 4.98 (d, J = 16.9 Hz, 1 H, CH=CHH),
5.80 (ddt, J = 16.9, 10.3, 6.7 Hz, 1 H, CH=CH2), 7.13 (m, 2 H,
Ph), 7.17 (m, 1 H, Ph), 7.26 (m, 2 H, Ph) ppm. 13C NMR (75 MHz,
CDCl3, 25 °C): δ = 19.4, 27.0, 28.9, 29.2, 29.7, 33.8, 35.0, 36.7,
43.7, 114.1, 125.5, 128.0 (ϫ2), 129.1 (ϫ2), 139.2, 141.6 ppm. GC–
MS (EI, 70 eV): tR = 17.01 min [m/z (%) = 230 (24) [M]+, 215 (1)
[M – 15]+, 188 (2), 138 (5), 132 (15), 118 (25), 91 (100), 83 (58), 69
(34), 55 (56), 41 (27)].
69 (24), 55 (34), 41 (23)].
In the same manner, iodization of (S)-12 (2.89 g, 12 mmol) gave
(S)-13 (3.70 g, 10 mmol, 89%) as an oil. [α]2D3 = –6.41 (c = 1.84,
CHCl3).
2,12-Dimethyl-1-phenyl-11-phenylsulfonyltetradecane [(2R,11SR,12R)-,
(2R,11SR,12S)-, (2S,11SR,12R)-, and (2S,11SR,12S)-14]: BuLi
(2.69 m in hexane, 3.1 mL, 8.4 mmol) was added to a stirred solu-
tion of (R)-4 (1.78 g, 8.4 mmol) in THF (70 mL) at –35 °C under
an argon atmosphere by using a syringe. After stirring at –35 °C
for 20 min, (R)-13 (2.51 g, 7 mmol) and HMPA (1.51 g, 8.4 mmol)
dissolved in THF (4 mL) was added dropwise. The mixture was
warmed gradually to room temperature and stirred for 8 h. The
resulting mixture was poured into HCl (1 n) and the crude product
was extracted with EtOAc, washed with sat. aq. NaHCO3 and
brine, dried with Na2SO4, and concentrated in vacuo. The residue
was purified by chromatography over SiO2 (50 g; hexane/EtOAc,
19:1) to afford (2R,11SR,12R)-14 (2.98 g, 6.7 mmol, 96%) as an
In the same manner, (R)-10 (7.30 g, 23 mmol) was treated with the
Grignard reagent to give (S)-11 (4.88 g, 21 mmol, 92%) as an oil.
[α]2D3 = –10.05 (c = 1.28, CHCl3).
9-Methyl-10-phenyldecan-1-ol [(R)- and (S)-12]: A solution of 9-
BBN (0.5 m in THF, 60 mL, 30 mmol) was added to a stirred solu-
tion of (R)-11 (4.61 g, 20 mmol) in THF (6 mL) at 0 °C under an
argon atmosphere by using a syringe. After stirring at room tem-
perature for 8 h, NaOH (1.2 g, 30 mmol) dissolved in H2O2 (30%, oil. IR (neat): ν = 3026 (m), 2925 (s), 2854 (s), 1603 (w, benzene
˜
10 mL) was added dropwise, and the mixture was stirred for 1 h at
room temperature. The resulting mixture was diluted with water
(50 mL), and the crude product was extracted with Et2O, washed
with brine, dried with Na2SO4, and concentrated in vacuo. The
residue was purified by chromatography over SiO2 (50 g; hexane/
EtOAc, 4:1) to afford (R)-12 (4.12 g, 17 mmol, 83%) as an oil.
ring), 1446 (s), 1304 (s, S=O), 1146 (s, S=O), 1084 (s), 723 (s), 698
(s) cm–1. 1H NMR (300 MHz, CDCl3, 25 °C): δ = 0.81 and 0.88 (t,
J = 7.4 Hz, 3 H, CH3CH2), 0.83 (d, J = 6.6 Hz, 3 H, CH3CH),
1.00 and 1.03 (d, J = 7.0 Hz, 3 H, CH3CH), 1.1–1.4 (m, 16 H),
1.6–2.1 (m, 4 H), 2.34 (dd, J = 13.3, 8.1 Hz, 1 H, CHHPh), 2.62
(dd, J = 13.3, 6.1 Hz, 1 H, CHHPh), 2.89 and 2.94 (td, J = 6.7,
2.0 Hz, 1 H, CHSO2), 7.13 (m, 2 H, Ph), 7.17 (m, 1 H, Ph), 7.26
(m, 2 H, Ph), 7.53 (m, 2 H, Ph), 7.60 (m, 1 H, Ph), 7.87 (m, 2 H,
[α]2D3 = –7.83 (c = 2.26, CHCl ). IR (neat): ν = 3342 (s, O–H), 3026
˜
3
(m), 2925 (s), 2854 (s), 1603 (m, benzene ring), 1454 (s), 1055 (s),
741 (s), 700 (s) cm–1. 1H NMR (300 MHz, CDCl3, 25 °C): δ = 0.83 Ph) ppm.
(d, J = 6.6 Hz, 3 H, CH3CH), 1.1–1.4 (m, 12 H), 1.4–1.6 (m, 2 H,
In the same manner, syntheses of (2R,11SR,12S)-14 from (S)-4 and
CH2CH2OH), 1.70 (m, 1 H, CH3CH), 2.34 (dd, J = 13.3, 8.2 Hz,
1 H, CHHPh), 2.63 (dd, J = 13.3, 6.0 Hz, 1 H, CHHPh), 3.62 (t,
J = 6.6 Hz, 2 H, CH2OH), 7.13 (m, 2 H, Ph), 7.17 (m, 1 H, Ph),
7.26 (m, 2 H, Ph) ppm. 13C NMR (75 MHz, CDCl3, 25 °C): δ =
19.4, 22.6, 25.2, 25.7, 27.1, 27.4, 29.4, 29.6, 29.8, 32.8, 34.6, 35.0,
36.7, 43.7, 125.5, 128.0 (ϫ2), 129.1 (ϫ2), 141.6 ppm. GC–MS (EI,
70 eV): tR = 27.91 min [m/z (%) = 248 (24) [M]+, 230 (6) [M –
18]+, 157 (3), 118 (15), 91 (100), 83 (70), 69 (51), 55 (62), 41 (25)].
(R)-13, (2S,11SR,12R)-14 from (R)-4 and (S)-13, and
(2S,11SR,12S)-14 from (S)-4 and (S)-13 were accomplished in a
similar yields (91–95%).
2,12-Dimethyl-1-phenyltetradecane [(2R,12R)-, (2R,12S)-, (2S,12R)-,
and (2S,12S)-15]: To magnesium turnings (3.16 g, 130 mmol)
stirred in anhydrous THF (3 mL), a catalytic amount of MeMgBr
(3.0 m, two drops) was added under an argon atmosphere to acti-
vate the metal. After stirring for 15 min at room temperature, a
solution of (2R,11SR,12R)-14 (2.83 g, 6.4 mmol) in anhydrous
MeOH (50 mL) was added by using a syringe, and the mixture was
stirred at 40 °C for 4 h. The mixture was evaporated to remove
MeOH and a cool H2SO4 solution (10%, 160 mL) was added to
dissolve the white residue. The crude product was extracted with
Et2O, washed with sat. aq. NaHCO3 solution and brine, dried with
Na2SO4, and concentrated in vacuo. The residue was purified by
chromatography over SiO2 (30 g; hexane) to afford (2R,12R)-15
(1.79 g, 5.9 mmol, 92%) as an oil. [α]2D3 = +2.92 (c = 1.99, CHCl3).
In the same manner, (S)-11 (4.61 g, 20 mmol) was treated with 9-
BBN to give (S)-12 (4.02 g, 16 mmol, 81%) as an oil. [α]2D3 = +8.80
(c = 1.25, CHCl3).
1-Iodo-9-methyl-10-phenyldecane [(R)- and (S)-13]: Iodine (5.72 g,
45 mmol) was added to a solution of triphenylphosphane (4.98 g,
19 mmol) and imidazole (2.18 g, 32 mmol) in anhydrous THF
(30 mL) at 0 °C under an argon atmosphere. After stirring for
15 min, (R)-12 (4.12 g, 17 mmol) dissolved in THF (7 mL) was
added by using a syringe. The mixture was stirred at 0 °C for 1 h,
and poured into sat. aq. Na2S2O3 and the product was extracted
with EtOAc. The extract was washed with water and brine, dried
with Na2SO4, and concentrated in vacuo. The residue was purified
by chromatography over SiO2 (50 g; hexane/EtOAc, 9:1) to afford
(R)-13 (4.80 g, 13 mmol, 81%) as an oil. [α]2D3 = +6.86 (c = 1.38,
IR (neat): ν = 3026 (m), 2924 (s), 2852 (s), 1604 (w, benzene ring),
˜
1456 (s), 1377 (m), 739 (m), 698 (s) cm–1. 1H NMR (300 MHz,
CDCl3, 25 °C): δ = 0.83 (d, J = 6.6 Hz, 3 H, CH3CH), 0.84 (d, J
= 6.2 Hz,3 H, CH3CH), 0.85 (t, J = 7.0 Hz, 3 H, CH3CH2), 1.1–
1.4 (m, 20 H), 1.70 (m, 2 H, 2ϫ CH3CH), 2.34 (dd, J = 13.3,
CHCl ). IR (neat): ν = 3024 (m), 2924 (s), 2852 (s), 1603 (m, benz- 8.2 Hz, 1 H, CHHPh), 2.63 (dd, J = 13.3, 6.0 Hz, 1 H, CHHPh),
˜
3
ene ring), 1454 (s), 741 (s), 698 (s) cm–1. 1H NMR (300 MHz,
CDCl3, 25 °C): δ = 0.84 (d, J = 6.7 Hz, 3 H, CH3CH), 1.1–1.4 (m,
12 H), 1.70 (m, 1 H, CH3CH), 1.81 (tt, J = 7.1, 7.1 Hz, 2 H,
CH2CH2I), 2.34 (dd, J = 13.3, 8.2 Hz, 1 H, CHHPh), 2.62 (dd, J
= 13.3, 6.0 Hz, 1 H, CHHPh), 3.18 (t, J = 7.1 Hz, 2 H, CH2I), 7.13
7.13 (d, J = 7.2 Hz, 2 H, Ph), 7.17 (d, J = 7.2 Hz, 1 H, Ph), 7.26
(dd, J = 7.2, 7.2 Hz, 2 H, Ph) ppm. 13C NMR (75 MHz, CDCl3,
25 °C): δ = 11.4, 19.2, 19.4, 27.1 (ϫ2), 29.5, 29.7 (ϫ3), 29.9, 30.0,
34.4, 35.0, 36.6, 36.7, 43.7, 125.5, 128.0 (ϫ2), 129.1 (ϫ2),
141.7 ppm. GC–MS (EI, 70 eV): tR = 24.49 min [m/z (%) = 302
Eur. J. Org. Chem. 2013, 6924–6933
© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
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