O. Rhode, H. M. R. Hoffmann / Tetrahedron 56 (2000) 6479±6488
6487
6
1
4
-Iodo-4a-methyl-2,3,4,4a,7,7a,8a,11,12,12a-decahydro-
H,10H-benzo[d]pyrano[2,3-b]-benzofuran (15, XI),
a-methyl-2,3,4,4a,7,7a,8a,11,12,12a-decahydro-1H,10H-
J3 Hz, 1H; H-7), 4.02±3.83 (m, 2H; H-4, H-11a), 3.69
(m, 1H; H-11b), 2.70±2.42 (m, 3H; H-3, H-8), 2.03±1.18
(m, 10H; CH ), 1.94 (s, 3H; CH ), 1.08 (s, 3H; CH ), 1.03 (s,
2
3
3
1
3
benzo[d]pyrano[2,3-b]-benzofuran (15, XH) and 5-
3H: CH ); C NMR (APT): d150.26 (1, C-2), 135.88 (1,
3
(
[
(
iodomethylene)-4a-methyl-dodecahydro-9H-indeno-
7a ,1 -4,5]furo[2,3-b]pyran (16). Cyclization precursor 14
C-5), 132.61 (1, C-6), 97.82 (2, C-7), 75.27 (2, C-1),
74.64 (2, C-4), 61.32 (1, C-11), 47.15 (2, C-8), 39.91
(1, C-3), 37.15 (1, CH ), 34.79 (1, CH ), 34.10 (1, C),
0
1 mmol) was allowed to react according to general pro-
0
2
2
cedure C (3 h). Chromatography afford two fractions. The
unpolar fraction contained 15(XI) and 15(XH), which
were separated by preparative DC (DCM). The polar frac-
tion contained 16. Data for 15(XI), yield (60 mg, 16%),
28.95 (2, CH ), 27.78 (2, CH ), 25.10 (1, CH ), 24.80 (1,
3 3 2
CH ), 21.16 (2, CH ), 19.28 (1, CH ); MS (70 eV): m/z
2
3
2
1
(%): 403 (1) [M 11], 275 (13), 257 (17), 250 (100), 229
(10), 187 (13), 159 (35), 123 (78), 105 (18), 95 (33), 84 (76).
1
colourless crystals, mp 101±1038C. H NMR: d5.88 (dd,
J2, 1 Hz, 1H; H-1), 4.98 (d, J5.6 Hz, 1H; H-7), 3.94 (m,
4-Iodomethylen-2-(2,6,6-trimethylcyclohex-1-enyl)-hexa-
hydro-pyrano[2,3-b]pyran (20). Reaction of cyclization
precursor 19 (0.5 mmol) according to general procedure C
(1 h) afforded 20 (68 mg, 34%). Reaction of 19 (0.5 mmol)
according to general procedure D (1.5 h) afforded 20
(103 mg, 51%), colourless crystals, mp 78±808C. IR
1
H; H-11a), 3.82 (dd, J11, 6 Hz, 1H; H-4), 3.53 (m, 1 H;
H-11b), 2.86 (ddd, J16, 6, 2 Hz, 1H; H-3a), 2.69 (ddd,
J16, 10, 2 Hz, 1H; H-3b), 2.28±1.17 (m, 13H; H-8,
CH ), 0.96 (s, 3H, CH ); MS (70 eV): m/z (%): 375 (2)
2
1
3
[
(
M ], 374 (6), 272 (10), 247 (8), 201 (8), 186 (4), 145
13), 131 (12), 106 (11), 91 (15), 84 (100), 67 (13). Data
2
1
(CHCl ): n3000 cm , 2932, 2868, 1612, 1456, 1376,
3
1
1
for 15(XH), yield (22 mg, 9%), colourless oil. H NMR:
1264, 1156, 1104, 1076, 1024, 984; H NMR: d6.03 (t,
d5.52 (ddd, J10, 5, 2 Hz, 1H; H-2), 5.18 (ddd, J10, 2,
J2 Hz, 1H; H-1), 4.82 (d, J3 Hz, 1H; H-7), 4.53 (dd,
J12, 3 Hz, 1H; H-4), 4.05 (br. dd, J11, 4.5 Hz, 1H;
H-11a), 3.55 (m, 1H; H-11b), 2.77 (dd, J14, 3 Hz, 1H;
H-3a), 2.61±2.38 (m, 1H; H-3b), 2.24 (m, 1H; H-8),
2.02±1.15 (m, 10H; CH ), 1.85 (s, 3H; CH ), 1.08 (s, 3H;
1
Hz, 1H; H-1), 5.00 (d, J5.5 Hz, 1H; H-7), 3.94 (m, 1H;
H-11a), 3.73 (dd, J10, 6 Hz, 1H; H-4), 3.52 (m, 1H;
H-11b), 2.43±1.15 (m, 15H; H-3, H-8, CH ), 0.94 (s, 3H;
2
1
CH ); MS (70 eV): m/z (%): 248 (21) [M ], 233 (19), 202
3
2
3
1
3
(
(
10), 187 (13), 161 (38), 147 (100), 133 (28), 120 (43), 106
86), 91 (98), 79 (58). Data for 16, yield (38 mg, 10%),
CH ), 1.02 (s, 3H; CH ); C NMR (APT): d144.92 (1,
3
3
C-2), 135.88 (1, C-5), 132.93 (1, C-6), 99.10 (2, C-7),
75.06 (2, C-1), 69.70 (2, C-4), 67.55 (1, C-11), 42.54
(2, C-8), 40.96 (1, C-3), 39.88 (1, CH ), 34.98 (1,
2
1
colourless crystals, mp 838C. IR (®lm): n3000 cm ,
2
9
936, 2860, 1452, 1380, 1248, 1184, 1148, 1132, 1084,
2
1
84; H NMR: d5.77 (t, J2 Hz, 1H; H-1), 5.48 (d,
CH ), 34.13 (1, C), 28.70 (2, CH ), 27.61 (2, CH ),
2
3
3
J3 Hz, 1H; H-7), 4.53 (dd, J9, 4 Hz, 1H; H-4), 3.84±
24.07 (1, CH ), 21.10 (2, CH ), 20.57 (1, CH ), 19.25
2 3 2
1
(1, CH ); MS (70 eV): m/z (%): 402 (3) [M ], 275 (15),
3
.55 (m, 2H; H-11), 2.94 (ddd, J18, 9, 2 Hz, 1H; H-3a),
2
2
.53 (ddd, J18, 4, 2 Hz, 1H; H-3b), 1.95±1.10 (m, 16H;
257 (11), 250 (100), 205 (6), 173 (12), 159 (26), 133 (12),
123 (94), 105 (20), 95 (41), 84 (74).
1
H-8, CH , CH ); MS (70 eV): m/z (%): 375 (4) [M ], 374
2
3
(
19), 273 (100), 211 (5), 181 (4), 146 (23), 131 (11), 117 (8),
106 (15), 91 (18), 79 (15).
5-(Iodomethylene)-dodecahydro-9H-methanoindeno-
0 0
[
7a ,1 -4,5]furo[2,3-b]pyran (22) and 2-(6,6-diethyl-bicy-
4
-Iodomethylen-2-(2,6,6-trimethylcyclohex-1-enyl)-hexa-
clo[3.1.1]hept-2-en-2-yl)-4-iodomethylene-hexahydro-
pyrano[2,3-b]pyran (23). Reaction of cyclization precursor
21 (0.5 mmol) according to general procedure C (5 min)
afforded 22 (84 mg, 42%, E/Z mixture, 1.5:1) as colourless
crystals, mp 94±968C. Reaction of 21 (0.5 mmol) according
to general procedure D (5 min) afforded 22 (84 mg, 42%,
E/Z mixture, 1.5:1) and 23 (22 mg, 11%) as colourless oil.
hydro-pyrano[2,3-b]pyran (18). Reaction of cyclization
precursor 17 (0.5 mmol) according to general procedure C
(
1 h) afforded 18 (30 mg, 15%, only one isomer). Reaction
of 17 (0.5 mmol) according to general procedure D (2.5 h)
afforded 18 (48 mg, 24%, E/Z mixture, 1:1). The isomers
could be separated by preparative DC, but were not identi-
®
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ed. Data for unpolar isomer, colourless crystals, mp 73±
Data for 22. IR (CHCl ): n3308 cm , 3008, 2944, 2920,
3
2
1
68C. IR (CHCl ): n3000 cm , 2932, 2868, 1652, 1468,
2872, 1612, 1404, 1344, 1268, 1248, 1152, 1080, 1032, 976;
3
1
1
1
364, 1284, 1172, 1136, 1096, 1052, 996; H NMR: d5.98
H NMR: d5.97 (dd, J7, 2 Hz, 1H; H-1), 5.28 (d,
(
2
d, J2 Hz, 1H; H-1), 4.73 (d, J3 Hz, 1H; H-7), 3.93 (m,
J4 Hz, 1H; H-7), 4.41 (dd, J8, 4 Hz, 1H; H-4), 3.88±
3.57 (m, 2H; H-11), 3.17±2.96 (m, 2H; H-3a, H-6), 2.65±
2.13 (m, 3H; H-3b, H-15a, H-16a), 2.03 (t, J6 Hz, 1H;
H-12), 1.98±0.81 (m, 7H; CH, CH ), 1.20 (s, 3H, CH ),
H; H-4, H-11a), 3.73 (m, 1H; H-11b), 2.96±2.82 (m, 1H;
H-3a), 2.81±2.60 (m, 1H; H-3b), 2.16 (dd, J16, 2 Hz, 1H;
H-8), 2.05±1.15 (m, 10H; CH ), 1.93 (s, 3H; CH ), 1.07 (s,
2
3
2
3
13
1
3
3
H; CH ), 0.94 (s, 3H; CH ); C NMR (APT): d149.17
1.04 (d, J10 Hz, 1H; H-15b), 0.81 (s, 3H; CH );
C
3
3
3
(
1, C-2), 135.58 (1, C-5), 132.72 (1, C-6), 97.37 (2, C-7),
5.07 (2, C-1), 74.94 (2, C-4), 61.52 (1, C-11), 45.02 (2,
C-8), 39.64 (1, C-3), 38.33 (1, CH ), 34.59 (1, CH ),
NMR (APT): d162.91 (1, C-2), 101.08 (2, C-7), 82.09
(2, C-4), 70.46 (2, C-1), 64.06 (1, C-11), 60.74 (1, C-5),
50.25 (2, C-12), 46.75 (1, C-3), 43.21 (2, C-8), 39.87 (2,
C-14), 38.38 (1, C-13), 37.70 (2, C-6), 35.00 (1, C-16),
7
2
2
34.03 (1, C), 28.88 (2, CH ), 27.77 (2, CH ), 24.50 (1,
CH ), 22.44 (1, CH ), 21.27 (2, CH ), 19.25 (1, CH ); MS
3 3
28.81 (1, C-15), 27.46 (2, CH ), 23.86 (1, C-10), 23.02
3
2
2
3
2
1
(70 eV): m/z (%): 402 (1) [M ], 275 (20), 257 (15), 250
(74), 229 (8), 201 (8), 187 (11), 159 (30), 135 (10), 123
(100), 105 (29), 91 (48), 84 (79). Data for unpolar isomer,
(1, C-9), 22.86 (2, CH ); MS (70 eV): m/z (%): 400 (4)
3
1
[M ], 299 (100), 273 (11), 250 (13), 235 (43), 201 (55), 173
(34), 143 (26), 129 (44), 105 (49), 91 (68), 79 (50); HRMS
calcd for C H O I: 400.0899, found 400.0906. Data for 23.
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1
colourless oil. IR (CHCl ): n3055 cm , 2931, 2245,
3
18 25
2
1
1
1
716, 1468, 1381, 1366, 1260, 1144, 1113, 1099, 1049,
H NMR: d6.06 (m, 1H; H-1), 5.43 (m, 1H; H-6), 4.79 (d,
1
000, 930; H NMR: d6.09 (s, 1H; H-1), 4.73 (d,
J3 Hz, 1H; H-7), 4.32 (m, 1H; H-4), 4.10±3.93 (m, 1H;