CHEMISTRY & BIODIVERSITY – Vol. 11 (2014)
1499
endo-13h, as described for cis-endo-6d. R (cyclohexane/AcOEt 99 :1) 0.24. IR: 3061, 2964, 2879, 2815,
f
2
6
713, 1715, 1465, 1382, 1329, 1246, 1227, 1191, 1165, 1095, 1082, 1055, 982, 961, 906, 868, 797, 778, 731, 683,
56. H-NMR: 9.41 (s, 1 H); 6.21 (dd, J¼2.5, 5.9, 1 H); 6.17 (dd, J¼2.5, 5.9, 1 H); 2.95 (br. s, 1 H); 2.45
1
(
1
br. s, 1 H); 1.90 (dq, J¼1.9, 7.2, 1 H); 1.88–1.81 (m, 1 H); 1.68 (dt, J¼1.3, 9.0, 1 H); 1.56–1.49 (m, 1 H);
13
.40 (dq, J¼1.6, 8.7, 1 H); 1.06 (d, J¼6.9, 3 H); 0.95 (t, J¼7.5, 3 H). C-NMR: 206.5 (d); 138.5 (d); 134.7
þ
(d); 60.2 (s); 50.0 (d); 46.7 (d); 44.1 (t); 39.5 (d); 24.3 (t); 16.9 (q); 10.2 (q). MS: 164 (3, M ), 135 (7), 108
(
8), 99 (26), 93 (11), 91 (9), 79 (10), 77 (7), 66 (100), 41 (12), 39 (11). Aldehyde, pine, borneol,
camphoraceous.
(
1RS,2RS,3RS,4SR)-2-Ethyl-3-methylbicyclo[2.2.1]hept-5-ene-2-carbaldehyde (cis-endo-6h). Ob-
tained in 88% yield from cis-endo-13h as described for cis-endo-6d. IR: 3061, 2963, 2876, 2701, 1712,
1
1
460, 1377, 1338, 1250, 1214, 1015, 983, 911, 881, 791, 775, 733, 693, 632. H-NMR: 9.45 (s, 1 H); 6.39 (dd,
J¼3.4, 5.8, 1 H); 6.18 (dd, J¼3.4, 5.8, 1 H); 2.82 (br. s, 1 H); 2.73 (br. s, 1 H); 2.17 (dq, J ¼ 3.1, 7.4, 1 H);
1
3
.90–1.81 (m, 1 H); 1.70–1.62 (m, 2 H); 1.49 (dt, J¼1.5, 8.6, 1 H); 0.95 (d, J¼7.4, 3 H); 0.88 (t, J¼7.3,
13
H). C-NMR: 208.6 (d); 137.5 (d); 135.6 (d); 61.2 (s); 48.6 (d); 48.5 (d); 47.1 (t); 46.9 (d); 29.9 (t); 16.4
þ
(q); 9.8 (q). MS: 164 (3, M ), 136 (9), 107 (12), 99 (24), 97 (5), 93 (11), 91 (11), 79 (13), 77 (9), 66 (100),
4
1 (10), 39 (9). Aldehyde-like, camphoraceous, moldy.
3aRS,4RS,7SR,7aRS)-2,3,3a,4,7,7a-Hexahydro-3aH-4,7-methanoindene-3a-carbaldehyde (exo-
i) ). Obtained in 38% yield as a 82 :18 exo/endo mixture, with 1.1 mol-equiv. of 2a and 0.1 mol-
(
59
6
equiv. of AlCl in toluene, at ꢀ208 for 5 h. Purification by CC (SiO ; cyclohexane/AcOEt 99 :1; R 0.25).
3
2
f
IR: 3060, 2950, 2867, 2807, 2693, 1713, 1446, 1341, 1325, 1244, 1075, 994, 897, 858, 842, 779, 735, 696, 666,
1
6
18. H-NMR: 9.74 (s, 1 H); 6.31 (dd, J¼2.3, 5.4, 1 H); 6.21 (dd, J¼3.0, 5.8, 1 H); 2.96 (br. s, 1 H); 2.89–
.85 (m, 1 H); 2.85 (br. s, 1 H); 1.87–1.80 (m, 1 H); 1.78–1.67 (m, 2 H); 1.63 (q, J¼8.7, 2 H); 1.58–1.48
2
13
(
(
(
m, 1 H); 1.30–1.21 (m, 1 H); 1.18–1.10 (m, 1 H). C-NMR: 205.1 (d); 138.9 (d); 136.0 (d); 51.7 (t); 68.6
þ
s); 50.8 (d); 47.2 (d); 46.4 (d); 29.9 (t); 29.8 (t); 29.5 (t). MS: 162 (9, M ), 105 (5), 97 (53), 95 (9), 91
18), 79 (9), 77 (10), 66 (100), 41 (6); 39 (10). endo-6i: R (cyclohexane/AcOEt 99 :1) 0.24. MS: 162 (14,
f
þ
M ), 105 (8), 97 (42), 95 (11), 91 (20), 79 (11), 77 (11), 67 (31), 66 (100), 65 (20), 41 (8); 39 (14).
Aldehydic, camphoraceous, pinanol, borneol.
(
1RS,4SR,4aSR,8aSR)-1,5,6,7,8,8a-Hexahydro-1,4-methanonaphthalene-4a(4H)-carbaldehyde (exo-
60
6
j) ). Obtained in 27% yield as a 80 :19 exo/endo mixture, with 1.1 mol-equiv. of 2a and 0.1 mol-equiv. of
AlCl in toluene, at ꢀ208 for 18 h. Purification by CC (SiO ; cyclohexane/AcOEt 99 :1; R 0.25). IR:
3
2
f
3
060, 2933, 2864, 2796, 2691, 1716, 1460, 1333, 1254, 1212, 1023, 993, 908, 890, 818, 785, 732, 694, 666.
1
H-NMR: 9.64 (s, 1 H); 6.27 (dd, J¼2.7, 5.7, 1 H); 6.17 (dd, J¼3.0, 5.5, 1 H); 2.82 (br. s, 1 H); 2.81 (br. s,
1
H); 2.43 (ddd, J¼3.6, 5.5, 12.9, 1 H); 1.79 (dt, J¼1.1, 5.3, 1 H); 1.76 (dt, J¼1.1, 5.3, 1 H); 1.59–1.47 (m,
H); 1.35 (dt, J¼1.9, 8.4, 1 H); 1.26 (dt, J¼1.7, 8.4, 1 H); 1.24–1.14 (m, 1 H); 1.09 (dt, J¼6.3, 13.3, 2 H);
1
0
3
13
.70 (dq, J¼3.8, 13.3, 2 H). C-NMR: 206.4 (d); 138.2 (d); 134.5 (d); 57.6 (s); 48.6 (d); 46.9 (d); 46.0 (t);
þ
9.6 (d); 24.9 (t); 24.4 (t); 19.8 (t); 18.1 (t). MS: 176 (2, M ), 111 (58), 95 (5), 93 (7), 91 (15), 81 (22), 79
(
8), 77 (12), 66 (100), 53 (8), 41 (8), 39 (11).
1RS,4SR,4aRS,8aRS)-1,5,6,7,8,8a-Hexahydro-1,4-methanonaphthalene-4a(4H)-carbaldehyde
endo-6j). Obtained in 2% yield during the purification of exo-6j. R (cyclohexane/AcOEt 99 :1) 0.20. IR:
(
(
f
3
060, 2933, 2864, 2796, 2691, 1716, 1460, 1333, 1254, 1212, 1023, 993, 908, 890, 818, 785, 732, 694, 666.
1
H-NMR: 9.40 (s, 1 H); 6.19 (dd, J¼2.5, 5.9, 1 H); 5.98 (dd, J¼2.8, 5.9, 1 H); 2.68 (br. s, 1 H); 2.59 (br. s,
1
1
H); 1.94 (ddd, J¼1.6, 6.5, 14.0, 1 H); 1.84 (ddd, J¼1.6, 6.5, 14.0, 1 H); 1.78 (dt, J¼1.3, 9.0, 1 H); 1.72–
.58 (m, 2 H); 1.56 (br. s, 1 H); 1.46–1.38 (m, 2 H); 1.35–1.12 (m, 3 H). 13C-NMR: 205.9 (d); 138.3 (d);
þ
1
32.6 (d); 57.3 (s); 50.2 (d); 48.6 (d); 44.4 (t); 40.1 (d); 26.4 (t); 25.5 (t); 19.6 (t); 17.5 (t). MS: 176 (8, M ),
1
20 (15), 111 (40), 105 (8), 91 (19), 81 (18), 79 (20), 77 (14), 66 (100), 53 (6), 41 (7), 39 (10).
Camphoraceous, woody, terpenic, liquorice.
1RS,2SR,3SR,4SR)-3-(Chloromethyl)-2-methylbicyclo[2.2.2]oct-5-ene-2-carbaldehyde (endo-8a).
(
Obtained in 92% yield as a 18 :76 exo/endo mixture, with 2.0 mol-equiv. of 7 and 0.1 mol-equiv. of
AlCl3 in toluene, at 208 for 24 h. Purification by CC (SiO ; cyclohexane/AcOEt 99 :1; R 0.13). R
f
2
f
(
cyclohexane/AcOEt 95 :5) 0.26. M.p.: 78.4–79.68. IR: 3047, 2930, 2874, 2704, 1722, 1477, 1453, 1366,
5
6
9
20
)
)
For (þ)-(3aS,4S,7R,7aS)-exo-6i, [a] ¼ þ20.0 (c¼1.27, CHCl ; 96% ee), see [13h].
D
3
0
20
For (ꢀ)-(1S,4R,4aR,8aR)-exo-6j, [a] ¼ ꢀ21.3 (c¼0.82, CH Cl ; 82% ee), see [13j].
D
2
2