Helvetica Chimica Acta Vol. 87 (2004)
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Data of 28a (first eluted): Colorless oil. [a]2D3 À2.54 (c 0.63, CHCl3). 1H-NMR (500.13 MHz, CDCl3):
5.76 (ddd, J 17.26, 10.02, 7.41, CH2CH); 4.98 (dm, J 17.26, 1 H, CH2CH); 4.90( dm, J 10.02, 1 H,
CH2CH); 3.96 3.83 (m, OCH2CH2O); 2.70( m, 1 HÀC(6)); 2.29 (m, HÀC(4)); 2.01 (m, HÀC(1)); 1.81
(ddd, J 13.13, 4.55, 3.03, 1 HÀC(3)); 1.60( ddd, J 11.96, 8.93, 2.70, 1 HÀC(5)); 1.55 (dm, J 10.11,
1 HÀC(7)); 1.46 (dd, J 13.13, 3.37, 1 HÀC(3)); 1.41 (dm, J 10.11, 1 HÀC(7)); 1.36 (dm, J 11.96,
1 HÀC(5)). NOE: 2.01 (2.92, 2.70), 1.60 (3.34, 2.70), 1.81 (3.79, 2.29), 1.60 1.36 (9.20, 2.29), 3.96 3.83
(4.44, 2.01), 2.70 (3.40, 2.01), 1.55 (1.76, 2.01), 1.41 (2.07, 2.01), 2.29 (4.54, 1.81), 1.46 (17.55, 1.81), 2.70 (11.12,
1.60), 2.29 (2.37, 1.60), 1.36 (24.65, 1.60), 2.29 (3.55, 1.55), 2.01 (4.29, 1.55), 1.41 (15.31, 1.55), 2.29 (2.26, 1.46),
1.80(17.68, 1.46), 2.70(1.54, 1.36), 2.29 (4.64, 1.36), 1.60(19.53, 1.36). 13C-NMR (50.3 MHz, CDCl3): 142.99
(CH2CH); 116.02 (CH2CH); 112.30(C(2)); 64.48, 63.76 (O CH2CH2O); 49.49 (C(1)); 43.11 (C(3)); 38.62,
35.96 (C(4), C(6)); 35.90, 34.93 (C(5), C(7)). CI-MS (CH4): 209 (3, [M 29] ), 182 (11, [M 2] ), 181 (100,
[M 1] ), 180(45, M ), 179 (18, [M À 1] ), 165 (1), 153 (2), 152 (2), 151 (3), 137 (5), 126 (7), 125 (4), 113 (4),
112 (4), 99 (7), 93 (7), 92 (11), 87 (4), 73 (8). HR-EI-MS (pos.): 180.1149 (C11H16O2 ; calc. 180.1145).
Data of 28b: Colorless oil. [a]2D4 49.9 (c 1.33, CHCl3). 1H-NMR (500.13 MHz, CDCl3): 5.77 (ddd, J
17.33, 10.13, 7.35, CH2CH); 4.95 (dm, J 17.33, 1 H, CH2CH); 4.89 (dm, J 10.13, 1 H, CH2CH); 3.95
3.81 (m, OCH2CH2O); 2.22 (m, HÀC(5)); 2.15 (m, HÀC(1)); 2.11 (m, HÀC(4)); 1.97 (ddd, J 12.80, 8.59,
2.27, 1 HÀC(6)); 1.85 (dd, J 13.31, 4.89, 1 HÀC(3)); 1.54 (dm, J 10.19, 1 HÀC(7)); 1.50( dd, J 13.31, 3.40,
1 HÀC(3)); 1.43 (dm, J 10.19, 1 HÀC(7)); 1.22 (ddd, J 12.80, 4.57, 4.55, 1 HÀC(6)). NOE: 1.97 (3.11, 2.22),
2.22 (5.20, 1.97), 1.22 (16.05, 1.97), 2.15 (1.91, 1.54), 2.11 (1.59, 1.54), 1.43 (17.63, 1.54), 2.15 (3.59, 1.43), 2.11
(1.99, 1.43), 1.54 (14.40, 1.43), 2.22 (5.55, 1.22), 2.15 (7.70, 1.22), 1.97 (15.11, 1.22). 13C-NMR (50.3 MHz,
CDCl3): 143.57 (CH2CH); 116.02 (CH2CH); 112.20(C(2)); 64.44, 63.82 (O CH2CH2O); 44.28, 44.17, 41.44
(C(1), C(4), C(5)); 43.85, 34.88, 29.57 (C(3), C(6), C(7)). CI-MS (CH4): 209 (3, [M 29] ), 183 (1, [M 3] );
182 (14, [M 2] ), 181 (100, [M 1] ), 180(13, M ), 179 (15, [M À 1] ), 165 (2), 153 (2), 137 (36), 126 (39),
125 (6), 112 (6), 109 (6), 99 (8), 91 (4), 87 (9), 73 (22), 55 (3), 45 (11), 41 (24). Anal. calc. for C11H16O2: C 73.30,
H 8.95; found: C 73.14, H 8.82.
(1R,4R,5R)-Spiro[bicyclo[2.2.1]heptane-2,2'-[1,3]dioxolane]-5-ethanol (29). To a soln. of 28b (9.55 g,
53 mmol) in dry THF (100 ml), 0.5m 9-BBN ¥ THF complex soln. (233 ml, ca. 116.6 mmol) was added dropwise
at 08 under N2. After the addition was complete (3 h), the mixture was stirred for 5 h at r.t. and then cooled to 98
before 3m aq. NaOH (180ml) was added. The thus obtained trialkylborane was oxidized by slow dropwise
addition of 30% H2O2 soln. (180ml) at 0 8. After stirring overnight at r.t., the mixture was extracted with AcOEt
(4 Â 200 ml), the combined extract washed with sat. Na2S2O3 soln. (3 Â 80ml) and brine (2 Â 80ml), dried
(Na2SO4), and evaporated, and the residue purified by CC (AcOEt/CH2Cl2 1:2): 10.19 g (97%) of 29 (Rf 0.39).
Colorless oil. [a]2D3 36.3 (c 0.54, CHCl3). 1H-NMR (500.13 MHz, CDCl3): 3.96 3.82 (m, OCH2CH2O);
3.67 3.63 (m, CH2CH2OH); 2.13 (m, HÀC(1)); 2.03 (m, HÀC(4)); 1.93 (ddd, J 12.64, 8.09, 2.11, 1 HÀC(6));
1.84 (dd, J 13.13, 4.80, 1 HÀC(3)); 1.65 1.58 (m, 3 H); 1.55 (dm, J 10.11, 1 HÀC(7)); 1.47 1.43 (m, 2 H);
1.41 (dm, J 10.19, 1 HÀC(7)); 0.97 (ddd, J 12.64, 4.38, 4.38, 1 HÀC(6)). 13C-NMR (50.3 MHz, CDCl3):
115.98 (C(2)); 64.48, 63.86 (OCH2CH2O); 61.64 (CH2CH2OH); 44.32 (C(3)); 44.17 (C(1)); 40.53 (C(4)); 39.73
(CH2CH2OH); 37.14 (C(5)); 34.78, 30.41 (C(6), C(7)). CI-MS (CH4): 239 (1, [M 41] ), 227 (1, [M 29] ), 200
(10, [M 2] ), 199 (86, [M 1] ), 198 (27, M ), 197 (17, [M À 1] ), 183 (2), 182 (11), 181 (100), 167 (1), 153
(12), 137 (5), 126 (6), 119 (4), 99 (5), 87 (3), 73 (3). Anal. calc. for C11H18O3: C 66.64, H 9.15; found: C 66.62,
H 9.34.
(1R,4R,5R)-5-(2-Hydroxyethyl)bicyclo[2.2.1]heptan-2-one (30). As described for rac-syn-26a, with 29
(9.93 g, 50.1 mmol). Purification of the product (Rf 0.34) by CC (silica gel, AcOEt/CH2Cl2 1 :2) yielded 30 7.26 g
(94%). Colorless oil. [a]2D3 53.2 (c 0.44, CHCl3). IR (CHCl3): 1740. 1H-NMR (500.13 MHz, CDCl3): 3.74
3.65 (m, CH2CH2OH); 2.58 (m, HÀC(1)); 2.44 (m, HÀC(4)); 2.09 (dd, J 17.69, 4.70, 1 HÀC(3)); 1.85
(dd, J 17.69, 2.96, 1 HÀC(3)); 1.83 1.71 (m, 4 H); 1.70( m, 1 H); 1.66 (dm, J 10.61, 1 HÀC(7)); 1.56
(m, 1 H); 1.38 (dm, J 12.29, 2 HÀC(6)). 13C-NMR (50.3 MHz, CDCl3): 217.88 (C(2)); 61.34 (CH2CH2OH);
50.19 (C(1)); 45.61 (C(4)); 39.99 (C(3)); 39.38 (CH2CH2OH); 36.74 (C(5)); 34.72, 31.82 (C(6), C(7)). CI-MS
(CH4): 195 (4, [M 41] ), 183 (9, [M 29] ), 156 (16, [M 2] ), 155 (100, [M 1] ), 154 (10, M ), 137 (25),
119 (12), 111 (13), 110 (14), 109 (27), 108 (9), 107 (7), 93 (39), 79 (6), 67 (8), 55 (3). Anal. calc. for C9H14O2:
C 70.10, H 9.15; found: C 69.96, H 9.40.
(1R,2S,4R)-Spiro[bicyclo[2.2.1]hept-5-ene-2,2'-oxirane] (18). To a soln. of 17 [17] (185 g, 0.911 mol) in
MeOH (480ml), K 2CO3 (252 g, 1.822 mol) was added at r.t. After 10h stirring, ice-cold H 2O (960ml) was
added, and the mixture was extracted with Et2O (4 Â 200 ml). The combined extract was washed with brine (4 Â
100 ml) and dried (MgSO4), the solvent distilled off through a short Vigreux column, and the residue purified by
CC (pentane/Et2O 6 :1): 102.4 g (92%) of 18 besides the 2-O-methyl ether corresponding to 19 (2.81 g, 2%).