Helvetica Chimica Acta Vol. 87 (2004)
2015
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22.8( q, MeÀC(1)); 16.8( q, MeexoÀC(3)); 15.2 (q, C(3')). EI-MS: 194 (3, M ), 179 (6, [M À CH3] ), 151 (10),
123 (23), 111 (97), 97 (24), 81 (78), 69 (100), 55 (37).
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Data of (E)-2. a À31.0 (c 1.0, CH2Cl2). IR (film): 3513w, 3030m, 2961vs, 2872vs, 1460s, 1377m,
1328m, 1264m, 1199w, 1166w, 1131m, 1100m, 1066m, 1025m, 1007s, 98 1s, 924m, 739w. 1H-NMR (600 MHz,
CDCl3): 5.60 5.56 (m, HÀC(1'), HÀC(2')); 1.96 (dddd, J 12.5, 11.0, 5.5, 2.4, HendoÀC(5)); 1.76 1.65
(m, Me(3'), HÀC(4), HendoÀC(6), HsynÀC(7)); 1.43 (dddd, J 16.5, 12.4, 5.3, 4.3, HexoÀC(6)); 1.21 (br. s, OH);
1.15 (dd, J 10.2, 1.4, HantiÀC(7)); 1.05 (td, J 12.5, 3.6, HexoÀC(5)); 0.90 (s, MeÀC(1)); 0.87 (s, Me2C(3)).
13C-NMR (150 MHz, CDCl3): 136.1 (d, C(1')); 120.5 (d, C(2')); 81.8 (s, C(2)); 52.4 (s, C(3)); 48.6 (d, C(4)); 44.7
(s, C(1)); 40.7 (t, C(7)); 29.3 (t, C(5)); 28.9 (q, MeendoÀC(3)); 25.7 (t, C(6)); 22.1 (q, MeÀC(1)); 17.7 (q, C(3'));
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17.4 (q, MeexoÀC(3)). EI-MS: 194 (2, M ), 179 (5, [M À CH3] ), 151 (8), 123 (14), 111 (91), 97 (19), 81 (65),
69 (100), 55 (40).
2.4. (1R,2R,4S)-1,3,3-Trimethyl-2-(1-methylethenyl)bicyclo[2.2.1]heptan-2-ol (3). GP 1, with 5.00 g
(32.8mmol) of ( À)-fenchone. The crude product was filtered through a pad of SiO2 using hexane/AcOEt
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40 :1 to give 3 (6.13 g, 96%) as a colorless oil. a À18.9 (c 1.0, CH2Cl2). IR (film): 3506m, 3105w, 2962vs,
2932vs, 2876vs, 1637m, 1464vs, 1386s, 1366s, 1316m, 1295m, 1240w, 1197w, 1159w, 1110w, 1063s, 1031m, 1009s,
978s, 952m, 903vs, 8 31w. 1H-NMR (600 MHz, CDCl3): 5.01 (t, J 1.5, HÀC(2'), NOE with MeÀC(1')); 4.97
(s, HÀC(2')); 2.13 2.04 (m, HendoÀC(5)); 2.03 (dq, J 10.4, 2.0, HsynÀC(7)); 1.81 (s, MeÀC(1')); 1.70 1.63
(m, HÀC(4), HendoÀC(6)); 1.41 1.38( m, HexoÀC(6)); 1.32 (td, J 12.6, 3.6, HexoÀC(5)); 1.18( dd, J 10.4, 1.4,
HantiÀC(7)); 0.99 (s, MeexoÀC(3)); 0.98( s, MeÀC(1)); 0.93 (s, MeendoÀC(3)). 13C-NMR (150 MHz, CDCl3):
144.9 (s, C(1')); 112.3 (t, C(2')); 85.1 (s, C(2)); 52.4 (s, C(3)); 49.6 (d, C(4)); 44.6 (s, C(1)); 41.3 (t, C(7)); 30.2
(t, C(5)); 28.9 (q, MeendoÀC(3)); 26.9 (t, C(6)); 24.9 (q, MeÀC(1)); 23.8( q, MeÀC(1')); 22.2 (q, MeexoÀC(3)).
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EI-MS: 194 (5, M ), 179 (12, [M À CH3] ), 151 (16), 123 (59), 111 (92), 95 (30), 81 (100), 69 (96), 55 (61).
Anal. calc. for C13H22O (194.32): C 80.35, H 11.41; found: C 80.22, H 11.36.
2.5. (1R,2R,4S)-1,3,3-Trimethyl-2-[(E)-1-methylprop-1-en-1-yl]bicyclo[2.2.1]heptan-2-ol (4). A flame-
dried flask was flushed with Ar gas and charged with Li dispersion (30% in mineral oil, 0.33 g, 47.1 mmol).
After washing the Li dispersion with anh. Et2O (3 Â 20 ml), Et2O (30 ml) was transferred into the flask, and
(E/Z)-2-bromobut-2-ene (2.44 ml, 21.4 mmol) was added dropwise under vigorous stirring at r.t. The resulting
grey suspension was stirred for 2 h at r.t. The precipitated LiBr was allowed to settle, and the resulting soln. was
transferred by cannula through a glass-wool pad into a flask cooled to À 208, containing a suspension of (À)-
fenchone (2.5 g, 11.9 mmol) and CeCl3 (3.23 g, 13.1 mmol) in THF (25 ml). This mixture was then warmed to r.t.
and stirring was continued for 5 h at that temp. The resulting dark-red suspension was poured into a separatory
funnel containing crushed ice, H2O (200 ml), and Et2O (100 ml). A 10% aq. HCl soln. was added with stirring
until the mixture became clear (pH < 3). The org. layer was washed with H2O (2Â). The aq. layers were
extracted with Et2O (2 Â 50 ml). The combined org. layers were washed with a sat. soln. of NaHCO3 and brine,
dried (MgSO4), filtered, and evaporated under reduced pressure. The residue was purified by CC (hexane/
AcOEt 40 :1) to give (E)-4 (1.07 g, 43%) as a colorless oil. A minor amount (ca. 15%) of (Z)-4 was evident from
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1H- and 13C-NMR analyses. a À23.6 (c 1.0, CH2Cl2). IR (film): 3562s, 3026s, 2952vs, 2873vs, 1464vs, 1385s,
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1375s, 1364s, 1347m, 1320m, 1262m, 1233m, 1205m, 1163w, 1114m, 1057vs, 1030s, 1007vs, 970vs, 903w, 8 76w,
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811w. H-NMR (600 MHz, CDCl3): 5.59 5.57 (m, HÀC(2')); 2.05 (dddd, J 12.6, 11.4, 5.8, 2.3, HendoÀC(5));
1.79 1.68( m, HendoÀC(6), MeÀC(1',2')); 1.62 1.56 (m, HÀC(4), HsynÀC(7)); 1.46 1.37 (m, HexoÀC(6)); 1.09
(dd, J 11.1, 1.2, HantiÀC(7)); 1.07 (s, MeendoÀC(3)); 1.02 0.95 (m, HexoÀC(5)); 1.01 (s, MeexoÀC(3)); 0.91
(s, MeÀC(1)). 13C-NMR (150 MHz, CDCl3): 145.0 (s, C(1')); 130.3 (d, C(2')); 79.5 (s, C(2)); 52.4 (s, C(3)); 50.3
(d, C(4)); 44.6 (s, C(1)); 41.3 (t, C(7)); 30.9 (t, C(5)); 28.0 (q, MeendoÀC(3)); 25.3 (t, C(6)); 23.02, 22.97
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(2q, MeÀC(1), MeexoÀC(3)); 18.44, 18.38 (2q, MeÀC(1',2'). EI-MS: 208(7, M ), 194 (2), 165 (4), 153 (48), 135
(6), 125 (43), 109 (15), 95 (13), 81 (71), 69 (100), 55 (50).
2.6. (1R,2R,4S)-1,3,3-Trimethyl-2-[(trimethylsilyl)ethynyl]bicyclo[2.2.1]heptan-2-ol (5). To a stirred soln.
of 1-(trimethylsilyl)ethyne (5.28ml, 38.18mmol) in anh. THF (200 ml), a 2.4 m soln. of BuLi in hexane
(15.11 ml, 36.28mmol) was slowly added via syringe at À 108. The resulting pale yellow lithium actylide soln.
was stirred for 30 min at À 108, and then added via cannula to a suspension of (À)-fenchone (4.36 g, 28.63 mmol)
and CeCl3 (5.65 g, 22.92 mmol) in THF (140 ml), as described in GP 1. The crude product was filtered through a
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pad of silica gel using hexane/AcOEt 40 :1 to give 5 (7.10 g, 99%) as a dark-yellow oil. a 17.2 (c 1.0,
CH2Cl2). IR (film): 3476m, 2960vs, 2932vs, 2900s, 2874s, 2164m, 1461s, 1386m, 1376m, 1366m, 1319m, 1304m,
1210w, 1112s, 1064s, 1038s, 1009s, 913w, 858vs, 842vs, 760s, 698w. 1H-NMR (300 MHz, CDCl3): 1.94 (dddd, J
12.7, 11.3, 5.9, 2.2, HendoÀC(5)); 1.82 1.76 (m, HÀC(4), HendoÀC(6), HsynÀC(7), OH); 1.39 (dddd, J 16.7,
12.6, 6.0, 4.0, HexoÀC(6)); 1.28( s, MeÀC(1)); 1.23 (s, MeexoÀC(3)); 1.21 (dd, J 10.3, 1.7, HantiÀC(7)); 1.20
(td, J 12.7, 3.7, HexoÀC(5)); 1.05 (s, MeendoÀC(3)); 0.26 (s, Me3Si). 13C-NMR (75 MHz, CDCl3): 107.8