The Journal of Organic Chemistry
NOTE
previously reported.23 IR (neat) νmax 2920, 2880, 1644, 1373, 1179, 1081,
944, 886, 822 cmꢀ1; 1H NMR (500 MHz, CDCl3) δ 5.94 (br s, 1 H), 5.13
(s, 1 H), 4.73 (s, 1 H), 4.71 (s, 1 H), 3.88ꢀ4.02 (m, 4 H), 1.82ꢀ2.22
(m, 6 H), 1.73 (s, 3 H), 1.42ꢀ1.52 (m, 1 H); 13C NMR (125 MHz,
CDCl3) δ 149.7, 134.9, 127.8, 109.0, 106.4, 65.5, 65.5, 41.3, 30.6, 27.4, 22.6,
20.9; HRMS (EI) calcd for C12H18O2: 194.1307; found 194.1302.
KMnO4); IR (neat) νmax 2919, 2854, 1643, 1449, 1379, 885, 545 cmꢀ1
;
1H NMR (500 MHz, CDCl3) δ 4.67 (s, 2 H), 2.11 (t, 1 H), 1.66ꢀ1.75
(m, 5 H), 0.83ꢀ1.40 (m, 12 H), 0.77 (d, J = 6.7 Hz, 3 H), 0.74 (s, 3 H);
13C NMR (125 MHz, CDCl3) δ 151.5, 108.3, 46.8, 44.5, 43.7, 40.9, 37.3,
32.5, 31.3, 29.4, 29.3, 27.1, 21.2, 15.5, 11.6; HRMS (EI) calcd for
C15H26: 206.2035; found 206.2033.
General Hydrogenation Procedure (General Procedure A). A
50 mL Schlenk flask attached to a Firestone valve (Ace Glass, Inc.) was
flame-dried and cooled under vacuum (0.01 Torr). The flask was subjected
to 3 purge/evacuation cycles with dry Ar and then charged with dry,
degassedTHF(7mL). Diene(3.66 mmol) wasadded, andthesolutionwas
cooled to 0 °C. After 10 min, 9-BBN-H (7.33 mL, 3.66 mmol, 0.5 M in
THF) was added dropwise via gastight syringe over 30 min. The reaction
was stirred for 1 h at 0 °C, then 1 h at 25 °C. Pd/C (150 mg, 4.4 mol % Pd,
10% w/w Pd/C) was then added in one portion. The atmosphere was
replaced with H2 (1 atm) using 7 evacuation/purge cycles, and the resulting
black mixture was stirred vigorously. Reaction progress was monitored by
1H,2H-Dicyclopentadiene (5b). General procedure A and chro-
matography (pentane) produced the title compound as a colorless oil
(0.31 g, 64%), whose spectroscopic properties matched those previously
reported.22
(R)-Triethyl(5-methyl-2-(prop-1-en-2-yl)hexyloxy)silane
(6b). General procedure A and chromatography (hexanes) produced a
colorless oil (0.69 g, 70%). Rf = 0.70 (1:9 EtOAc/hexanes, KMnO4); IR
(neat) νmax 2955, 2934, 2916, 2876, 1460, 1096, 1005, 888, 814,
1
725 cmꢀ1; H NMR (500 MHz, CDCl3) δ 4.79 (dq, J = 2.9, 1.4 Hz,
1 H), 4.70 (dd, J = 1.5, 0.7 Hz, 1 H), 3.57 (dd, J = 9.9, 6.5 Hz, 1 H), 3.48
(dd, 1 H), 2.15 (m, 1 H), 1.65 (dd, J = 1.3, 0.9 Hz, 3 H), 1.48ꢀ1.54 (m,
2 H), 1.21ꢀ1.28 (m, 1 H), 1.08ꢀ1.14 (m, 2 H), 0.94 (t, J = 7.9 Hz, 9 H),
0.87 (dd, J = 6.6, 3.9 Hz, 6 H), 0.58 (q, J = 8.0 Hz, 6 H); 13C NMR (125
MHz, CDCl3) δ 146.6, 112.0, 66.4, 50.4, 36.8, 28.50, 27.6, 23.2, 22.7, 20.3,
7.1, 4.8; HRMS (EI) calcd for C16H34SiO: 271.2457; found 271.2450.
(R)-3-(Methoxymethyl)-2,6-dimethylhept-1-ene (7b). Gen-
eral procedure A and chromatography (1ꢀ8% Et2O/pentane) produced
a colorless oil (0.50 g, 81%). Rf = 0.59 (1:9 EtOAc/hexanes, KMnO4);
IR (neat) νmax 2954, 2925, 2869, 1451, 1366, 1193, 1114, 888 cmꢀ1; 1H
NMR (500 MHz, CDCl3) δ 4.82 (dd, J = 2.0, 1.6 Hz 1 H), 4.74 (m, 1 H),
3.27ꢀ3.36 (m, 5 H), 2.31 (m, 1 H), 1.66 (s, 3 H), 1.43ꢀ1.52 (m, 1 H),
1.38ꢀ1.42 (m, 1 H), 1.23ꢀ1.31 (m, 1 H), 1.09ꢀ1.13 (m, 2 H), 0.87
(dd, J = 6.6, 3.6 Hz, 6 H); 13C NMR (125 MHz, CDCl3) δ 142.2, 108.4,
72.0, 55.1, 43.7, 32.76, 24.5, 23.9, 19.2, 18.8, 15.3; HRMS (EI) calcd for
C11H22O: 170.1671; found 170.1672.
(R)-5-Methyl-2-(prop-1-en-2-yl)hexyl Acetate (8b). General
procedure A and chromatography (1ꢀ8% Et2O/pentane) produced as a
colorless oil (0.44 g, 60%). Rf = 0.55 (1:9 EtOAc/hexanes, KMnO4); IR
(neat) νmax 2956, 2932, 2871, 1742, 1767, 1365, 1226, 1035, 892 cmꢀ1; 1H
NMR (500 MHz, CDCl3) δ 4.82 (dd, J = 3.3, 1.7 Hz, 1 H), 4.72ꢀ4.76
(m, 1 H), 4.02 (d, J = 7.1 Hz, 2 H), 2.35 (dtd, J = 9.3, 7.1, 5.3 Hz, 1 H), 2.02
(s, 3 H), 1.66 (s, 3 H), 1.51 (dp, J = 13.3, 6.7 Hz, 3 H), 1.30ꢀ1.41 (m, 2 H),
1.09ꢀ1.15 (m, 2 H), 0.87 (dd, J = 6.6, 3.2 Hz, 6 H); 13C NMR (125 MHz,
CDCl3) δ 171.3, 145.0, 113.1, 66.7, 46.6, 36.5, 28.3, 27.6, 23.0, 22.6, 21.2,
19.4; HRMS (EI) calcd for C12H22O2: 198.1620; found 198.1617.
Hex-5-enylbenzene (9b). General procedure A and chromatog-
raphy (hexanes) produced a colorless oil (0.33 g, 57%). Rf = 0.40
(hexanes, KMnO4); IR (neat) νmax 3077, 3060, 3028, 2929, 2857, 1640,
1496, 1453, 909, 745, 697, 541 cmꢀ1; 1H NMR (500 MHz, CDCl3) δ
7.20 (m, 2 H), 7.10 (m, 3 H), 5.73 (m, 1 H), 4.89 (m, 2 H), 2.54 (t, J = 7.7
Hz, 2 H), 2.01 (dd, J = 14.3, 7.2 Hz, 2 H), 1.55 (m, 2 H), 1.37 (dt, J =
17.7, 7.6 Hz, 2 H); 13C NMR (125 MHz, CDCl3) δ 143.0, 139.2, 128.7,
128.6, 125.9, 114.7, 36.2, 33.9, 31.3, 28.9; HRMS (EI) calcd for C12H16:
160.1252; found 160.1251.
1
disappearance of olefinic protons via H NMR. An NMR sample was
prepared by removing an aliquot (100 μL), dilution with DCM, filtration
through Celite, and concentration. Following consumption of the desired
olefin, the atmosphere was replaced with Ar via 7 evacuation/purge cycles.
MNP dimer (382 mg, 2.19 mmol) was added in one portion, and the
resulting solution was stirred for 45 min. The reaction mixture was diluted
with Et2O, filtered through Celite, rinsed with Et2O and concentrated. The
residue was dissolved in Et2O (10 mL), cooled to 0 °C, treated with
ethanolamine (40 μL, 6.6 mmol), and stirred for 10 min. The resulting
white mixture was diluted with pentane, filtered through a plug of silica,
rinsed with pentane and concentrated to give crude product. Products 7b
and 8b were sometimes contaminated with MNP derived byproduct.
Dissolving the crude product in Et2O and washing with NH4Cl (aq)
removed the byproduct. The byproduct has characteristic 1H NMR signals:
1.25 (s), 1.50 (s) and is not observable by TLC.
1-Methyl-4-(prop-1-en-2-yl)cyclohexane (1b). General pro-
cedure A and chromatography (pentane) produced a colorless volatile
oil (0.45 g, 90%). Rf = 0.62 (hexanes, KMnO4); IR (neat) νmax 2948,
2922, 2851, 1644, 1448, 1376, 885 cmꢀ1; 1H NMR (500 MHz, CDCl3)
δ 4.71 (s, 2 H), 4.66 (s, 2 H), 1.18ꢀ1.90 (m, 26 H), 0.94 (d, J = 7.1 Hz,
3 H), 0.88 (d, J = 6.5 Hz, 3 H); 13C NMR (125 MHz, CDCl3) δ 151.4,
150.6, 108.7, 108.2, 45.6, 44.6, 35.8, 32.9, 32.2, 32.2, 32.2, 32.2, 32.0,
30.2, 28.6, 26.8, 23.1, 23.0, 21.7, 21.3, 20.3, 19.0; HRMS (EI) calcd for
C10H18: 138.1409; found 138.1408.
Triethyl((5S)-2-methyl-5-(prop-1-en-2-yl)cyclohexyloxy)-
silane (2b). General procedure A and chromatography (1ꢀ5% EtOAc/
hexanes) afforded an inseparable mixture of diastereomers as a colorless oil
(0.86 g, 88%). Rf = 0.75 (1:9 EtOAc/hexanes, KMnO4); IR (neat) νmax
1
2954, 2876, 1047, 1003, 886, 723 cmꢀ1; H NMR (500 MHz, CDCl3)
δ 4.65ꢀ4.75 (m, 2 H), 3.62ꢀ3.9 (m, 1 H), 1.13ꢀ2.42 (m, 12 H),
0.87ꢀ1.01 (m, 18 H), 0.56ꢀ0.63 (q, 6 H), 0.49ꢀ0.56 (q, 4 H); 13C
NMR (125 MHz, CDCl3) δ 150.8, 149.7, 108.7, 108.3, 73.3, 71.6, 44.8,
41.0, 38.2, 37.4, 35.0, 34.9, 31.8, 31.0, 28.6, 25.0, 21.0, 20.8, 19.0, 11.0, 7.1,
7.1,7.1,7.1, 6.9, 6.6, 5.9, 5.4, 5.3, 5.3, 5.2; HRMS (EI) calcd for C16H32OSi:
268.2222; found 268.2217.
(R)-4,8-Dimethylnon-1-ene (3b). General procedure A and
chromatography (pentane) produced a colorless volatile oil (0.31 g,
55%). Rf = 0.70 (hexanes, KMnO4); IR (neat) νmax, 2955, 2926, 2870,
1463, 1378, 993, 910 cmꢀ1; 1H NMR (500 MHz, CDCl3) δ 5.75ꢀ5.81
(m, 1 H), 4.96ꢀ5.00 (m, 2 H), 2.04ꢀ2.06 (m, 1 H), 1.86ꢀ1.88 (m, 1 H),
1.49ꢀ1.53 (m, 2 H), 1.25ꢀ1.31 (m, 3 H), 1.07ꢀ1.16 (m, 3 H), 0.86 (d, J =
6.7 Hz, 9 H);13C NMR (125 MHz, CDCl3) δ138.1, 115.7, 41.9, 39.7, 37.3,
33.2, 28.4, 25.3, 23.1, 23.0, 19.8; HRMS (EI) calcd for C11H22: 154.1722;
found 154.1724.
(3S,5S,8R,9S,10S,13S,14S,17R)-10,13-Dimethyl-17-(prop-
1-en-2-yl)hexadecahydro-1H-cyclopenta[a]phenanthren-3-ol
(10b). The general procedure was modified as follows: 2 equiv of 9-BBN-
H was used, 20 mol % Pd/C was used, and 2 equiv of MNP was used.
Instead of filtration after the addition of ethanolamine, the white slurry was
concentrated in the presence of silica gel, and chromatography (20%
EtOAc/hexanes) afforded a white solid (0.76 g, 66%). Rf = 0.40 (3:7
EtOAc/hexanes, KMnO4); IR (neat) νmax 3654 (br), 2978, 2898, 1063,
721 cmꢀ1; 1H NMR (500 MHz, CDCl3) δ 4.85 (br s, 1 H), 4.71 (br s,
1 H), 3.58 (m, 1 H), 0.82ꢀ2.05 (m, 22 H), 1.74 (s, 3 H), 0.81 (s, 3 H), 0.58
(s, 3 H); 13C NMR (125 MHz, CDCl3) δ 146.3, 110.8, 71.4, 57.5, 56.4,
54.6, 45.1, 43.5, 39.1, 38.3, 37.2, 36.0, 35.7, 32.4, 32.2, 31.6, 28.9, 25.6, 24.8,
24.3, 22.2, 21.4, 13.1, 12.5; HRMS (EI) calcd for C22H36O: 316.2766;
found 316.2764.
(1R,4aR,7R,8aS)-1,8a-Dimethyl-7-(prop-1-en-2-yl)decahy-
dronaphthalene (4b). General procedure A and chromatography
(pentane) produced a colorless oil (0.67 g, 89%). Rf = 0.62 (hexanes,
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dx.doi.org/10.1021/jo200262r |J. Org. Chem. 2011, 76, 4132–4138