C. Herber, B. Breit
FULL PAPER
31.0 (C-2), 34.1 (C-4), 41.2 (C-3), 55.3 (OCH3), 72.6 (CH2Ar), 75.6 min, 30.2 min isothermal), 2.5 mL/min He. [α]2D0 = +25.3 (c = 0.93
(C-1), 113.7 (2ϫ C-3Ј), 122.6 (C-6), 129.1 (2ϫ C-2Ј), 131.0 (C-1Ј), in CHCl3). 1H NMR (499.873 MHz, CDCl3): δ = 0.82 (d, 3J =
3
3
137.9 (C-5), 159.0 (C-4Ј) ppm; signal assignment based on C/H-
COSY NMR experiments. C18H28O2 (276.41): calcd. C 78.21, H
10.21; found C 78.07, H 10.21.
6.6 Hz, 3 H, CH3), 0.87 (d, J = 6.6 Hz, 3 H, CH3), 0.91 (d, J =
6.6 Hz, 3 H, CH3), 0.95 (t, 3J = 7.4 Hz, 3 H, 10-CH3), 1.07–1.13
(m, 4 H, 3- and 5-CH2), 1.54 (mc, 1 H, 4-CH), 1.84 (mc, 1 H, 2-
2
CH), 1.98 (mc, 2 H, 9-CH2), 2.16 (mc, 1 H, 6-CH), 3.18 (dd, J =
(2R,4R)-5-(4Ј-Methoxybenzyloxy)-2,4-dimethylpentan-1-ol [(+)-6]:
Through a solution of (–)-5 (276 mg, 1.00 mmol) in MeOH (10 mL)
at –78 °C was bubbled a stream of ozone (1 bubble/s) until a quan-
titative conversion was observed by TLC. Subsequently, the ozone
was removed by bubbling argon through this solution. NaBH4
(189 mg, 5.00 mmol, 5.0 equiv.) was added at –78 °C and then the
mixture was slowly warmed to room temp. NH4Cl solution (10 mL)
was added, the solution was extracted with ethyl acetate
(3ϫ10 mL), and dried (Na2SO4). An appropriate amount of silica
gel was added to the filtrate, which was then concentrated to dry-
ness. Flash chromatography (20:1 petroleum ether/tert-butyl methyl
ether) furnished alcohol (+)-6 (240 mg, 0.950 mmol, 95%) as a col-
9.0, 3J = 6.9 Hz, 1 H, 1-CH2), 3.26 (dd, 2J = 9.1, 3J = 5.9 Hz, 1 H,
1-CH2), 3.79 (s, 3 H, O-CH3), 4.41 (d, 2J = 11.7 Hz, 1 H, CH2-Ar),
2
3
4
4.44 (d, J = 11.7 Hz, 1 H, CH2-Ar), 5.21 (ddt, J = 15.3, 7.9, J
3
4
= 1.4 Hz, 1 H, 7-CH), 5.38 (dtd, J = 15.3, 6.3, J = 0.8 Hz, 1 H,
8-CH), 6.87 (m, 2 H, 3Ј-CH), 7.26 (m, 2 H, 2Ј-CH) ppm. 13C NMR
(125.709 MHz, CDCl3): δ = 14.1 (C-10), 16.8 (CH3), 19.8 (CH3),
21.0 (CH3), 25.6 (C-9), 27.3 (C-4), 30.9 (C-2), 34.0 (C-6), 40.7 (C-
3), 45.7 (C-5), 55.2 (O-CH3), 72.6 (CH2-Ar), 76.5 (C-1), 113.7 (2ϫ
C-3Ј), 129.1 (2ϫ C-2Ј), 129.9 (C-8), 131.0 (C-1Ј), 135.6 (C-7), 159.0
(C-4Ј) ppm. C21H34O2 (318.49): calcd. C 79.19, H 10.76; found C
79.07, H 10.77.
orless oil. [α]2D0
=
+13.5 (c
=
2.72 in CHCl3). 1H NMR
(2S,4S,6R)-7-(4Ј-Methoxybenzyloxy)-2,4,6-trimethyl-1-heptanol
[(–)-9]: The procedure was analogous to that used for the prepara-
(499.873 MHz, CDCl3): δ = 0.89 (pt, J = 6.2 Hz, 6 H, CH3), 1.21
(mc, 2 H, 3-CH2), 1.60 (br. t, 1 H, OH), 1.74 (mc, 1 H, 2- or 4- tion of (+)-6. From alkene (+)-8 (360 mg, 1.13 mmol) and NaBH4
2
3
CH), 1.88 (mc, 1 H, 2- or 4-CH), 3.24 (dd, J = 9.0, J = 6.4 Hz,
(214 mg, 5.65 mmol, 5.0 equiv.) was obtained alcohol (–)-9
(326 mg, 1.11 mmol, 98%) as colorless oil. [α]2D0 = –3.1 (c = 1.30 in
CHCl3). 1H NMR (400.136 MHz, CDCl3): δ = 0.81 (d, 3J = 6.9 Hz,
3 H, CH3), 0.86 (d, J = 6.9 Hz, 3 H, CH3), 0.88 (d, J = 6.4 Hz,
3 H, CH3), 0.98–1.07 (m, 2 H, CH2), 1.11–1.22 (m, 2 H, CH2), 1.38
2
3
1 H, CH2), 3.27 (dd, J = 8.9, J = 6.4 Hz, 1 H, CH2), 3.42 (mc, 2
H, CH2), 3.80 (s, 3 H, O-CH3), 4.43 (pt, J = 11.9 Hz, 2 H, CH2-
Ar), 6.88 (m, 2 H, 3Ј-CH), 7.25 (m, 2 H, 2Ј-CH) ppm. 13C NMR
(125.709 MHz, CDCl3): δ = 16.3 (CH3), 17.0 (CH3), 30.5 (CH),
3
3
33.0 (CH), 37.3 (C-3), 55.2 (O-CH3), 68.8 (C-1), 72.7 (-CH2-Ar), (br. s, 1 H, OH), 1.58 (mc, 1 H, CH), 1.69 (mc, 1 H, CH), 1.84 (mc,
2
3
76.3 (C-5), 113.7 (2ϫ C-3Ј), 129.1 (2ϫ C-2Ј), 130.7 (C-1Ј), 159.1
(C-4Ј) ppm. C15H24O3 (252.35): calcd. C 71.39, H 9.59; found C
71.09, H 9.53.
1 H, CH), 3.17 (dd, J = 9.0, J = 6.9 Hz, 1 H, 7-CH2), 3.26 (dd,
2J = 9.0, 3J = 5.6 Hz, 1 H, 7-CH2), 3.36 (dd, 2J = 10.3, 3J = 6.4 Hz,
1 H, 1-CH2), 3.45 (dd, J = 10.3, J = 5.4 Hz, 1 H, 1-CH2), 3.78
(s, 3 H, O-CH3), 4.41 (pt, J = 12.3 Hz, 2 H, CH2-Ar), 6.85 (m, 2
2
3
2
(2R,4R)-5-Iodo-1-(4Ј-methoxybenzyloxy)-2,4-dimethylpentane [(+)-
H, 3Ј-CH), 7.23 (m, 2 H, 2Ј-CH) ppm. 13C NMR (100.624 MHz,
CDCl3): δ = 16.4 (CH3), 17.1 (CH3), 19.1 (CH3), 27.1 (CH), 30.8
(CH), 33.2 (CH), 41.4 (CH2), 42.0 (CH2), 55.2 (O-CH3), 68.9 (C-
1), 72.6 (CH2-Ar), 76.2 (C-7), 113.7 (2ϫ C-3Ј), 129.1 (2ϫ C-2Ј),
130.9 (C-1Ј), 159.1 (C-4Ј) ppm. C18H30O3 (294.43): calcd. C 73.43,
H 10.27; found C 73.08, H 10.28.
[5b]
7]: To PPh3I2
(1.30 g, 2.52 mmol, 1.2 equiv.) and imidazole
(345 mg, 5.07 mmol, 2.4 equiv.) in CH2Cl2 (9 mL) was added drop-
wise a solution of the alcohol (+)-6 (530 mg, 2.10 mmol) in CH2Cl2
(4 mL) at room temp. under exclusion of light. The suspension was
stirred overnight. TLC showed a quantitative conversion of the
starting material. The suspension was concentrated in vacuo. Flash
chromatography (20:1 petroleum ether/tert-butyl methyl ether) fur-
nished the title compound (+)-7 (699 mg, 1.93 mmol, 92%) as a
colorless oil which was stored at –20 °C under exclusion of light.
[α]2D0 = +7.6 (c = 1.36 in CHCl3). 1H NMR (400.136 MHz, CDCl3):
δ = 0.91 (d, 3J = 6.9 Hz, 3 H, CH3), 0.95 (d, 3J = 6.4 Hz, 3 H,
(2R,4S,6S)-7-Iodo-1-(4Ј-methoxybenzyloxy)-2,4,6-trimethyl-1-
heptane [(–)-10]: The procedure was analogous to that used for the
preparation of (+)-7. From the alcohol (–)-9 (174 mg, 0.594 mmol),
[5b]
PPh3I2
(368 mg, 0.713 mmol, 1.2 equiv.) and imidazole (98 mg,
1.4 mmol, 2.4 equiv.) was obtained iodide (–)-10 (229 mg,
CH3), 1.16–1.33 (m, 2 H, 3-CH2), 1.61 (mc, 1 H, CH), 1.82 (mc, 1 0.567 mmol, 95%) as a colorless oil. [α]2D0 = –0.5 (c = 2.04 in
H, CH), 3.14 (dd, 2J = 9.5, 3J = 6.0 Hz, 1 H, 5-CH2), 3.18–3.25 CHCl3). 1H NMR (400.136 MHz, C6D6): δ = 0.73 (d, J = 6.4 Hz,
3
2
3
3
3
(m, 2 H, CH2), 3.27 (dd, J = 9.0, J = 6.0 Hz, 1 H, 1-CH2), 3.80 3 H, CH3), 0.75 (d, J = 6.9 Hz, 3 H, CH3), 0.91 (d, J = 6.9 Hz,
(s, 3 H, O-CH3), 4.42 (pt, J = 12.3 Hz, 2 H, CH2-Ar), 6.87 (m, 2 3 H, CH3), 0.92–1.08 (m, 3 H, CH2), 1.16–1.32 (m, 2 H, CH, CH2),
H, 3Ј-CH), 7.25 (m, 2 H, 2Ј-CH) ppm. 13C NMR (100.624 MHz, 1.43 (mc, 1 H, CH), 1.85 (mc, 1 H, CH), 2.77 (dd, J = 9.5, J =
2
3
2
3
CDCl3): δ = 17.1 (CH3), 18.3 (CH3), 20.3 (C-5), 31.1 (CH), 32.3 6.0 Hz, 1 H, 7-CH2), 2.83 (dd, J = 9.5, J = 4.7 Hz, 1 H, 7-CH2),
2
3
2
3
(CH), 40.8 (C-3), 55.3 (O-CH3), 72.7 (CH2-Ar), 75.9 (C-1), 113.8
3.14 (dd, J = 9.0, J = 6.4 Hz, 1 H, 1-CH2), 3.19 (dd, J = 9.0, J
(2ϫ C-3Ј), 129.1 (2ϫ C-2Ј), 130.8 (C-1Ј), 159.1 (C-4Ј) ppm. = 6.0 Hz, 1 H, 1-CH2), 3.32 (s, 3 H, O-CH3), 4.36 (pt, 2J = 12.3 Hz,
C15H23IO2 (362.25): calcd. C 49.73, H 6.40; found C 50.00, H 6.28.
2 H, CH2-Ar), 6.82 (m, 2 H, 3Ј-CH), 7.25 (m, 2 H, 2Ј-CH) ppm.
13C NMR (100.624 MHz, CDCl3): δ = 17.3 (CH3), 18.0 (CH3), 19.4
(CH3), 20.3 (C-7), 27.6 (CH), 31.3 (CH), 32.3 (CH), 41.9 (CH2),
44.9 (CH2), 54.8 (O-CH3), 72.9 (CH2-Ar), 76.2 (C-1), 114.1 (2ϫ C-
3Ј), 129.3 (2ϫ C-2Ј), 131.5 (C-1Ј), 159.7 (C-4Ј) ppm. C18H29IO2
(404.33): calcd. C 53.47, H 7.23; found C 53.64, H 7.26.
(2R,4S,6S,7E)-1-(4Ј-Methoxybenzyloxy)-2,4,6-trimethyldec-7-ene
[(+)-8]: The procedure was analogous to that used for the prepara-
tion of (–)-5. From o-DPPB ester (–)-3 (214 mg, 0.550 mmol,
1.1 equiv.), CuBr·SMe2 (56 mg, 0.275 mmol, 0.55 equiv.) and iodide
(+)-7 (181 mg, 0.500 mmol) was obtained alkene (+)-8 (131 mg,
0.410 mmol, 82%, dr 98:2) as a colorless oil after chromatographic
purification [flash chromatography (50:1 petroleum ether/MTBE)
followed by reversed phase chromatography (75:25, 80:20 acetoni-
trile/water, the product fractions were first concentrated in vacuo,
then extracted with CH2Cl2 and dried with CaCl2]. GC (CP-SIL 5
Lowbleed/MS; 30 mϫ0.32 mm ϫ 0.25 µm: 50 °C (5 min isother-
mal), Ǟ 150 °C (25 °C/min, 10 min isothermal), Ǟ 170 °C (25 °C/
(2R,4S,6S,8R,9E)-1-(4Ј-Methoxybenzyloxy)-2,4,6,8-tetramethyl-
undec-9-ene [(–)-11]: The procedure was analogous to that used for
the preparation of (+)-8. From o-DPPB ester (+)-2 (171 mg,
0.457 mmol, 1.1 equiv.), CuBr·SMe2 (46.4 mg, 0.226 mmol,
0.55 equiv.) and iodide (–)-10 (167 mg, 0.413 mmol) was obtained
alkene (–)-11 (121 mg, 0.350 mmol, 85%, dr Ͼ95:5, NMR) as a
colorless oil. [α]2D0 = –16.1 (c = 1.32 in CHCl3). 1H NMR
3516
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Eur. J. Org. Chem. 2007, 3512–3519