A. Chrobok et al. / Tetrahedron 63 (2007) 8336–8350
8347
2H, H(3000,3000), J3 ,2 ¼16.4, J3 ,2 ¼10.9), 5.83 (ddt, 1H,
OH(3)), 1.56 (s, 3H, CH3(7)), 1.62 (ddd, 1H, H(14endo),
J14,14¼12.8, J14,13¼3.0, J14,13b¼0.6), 2.05 (m, 1H, H(2),
000 000
000 000
H(2000), J2 ,3 ¼16.5, J2 ,3 ¼10.7, J2 1 wJ2 1 w7.1), 5.88
000 000
000 000
000 000
000 000
(dd,1H, H(500), J5 ,6 ¼9.85, J5 ,4 ¼5.06), 5.93 (dt, 1H,
J2,1¼12.1, J2,1¼8.4, J2;CH ¼6.8, J2,3¼3.4), 2.29 (dd, 1H,
00 00
00 00
3
H(600), J6 ,5 ¼9.85, J6 ,7 ¼J6 ,7 ¼4.04), 9.23 (br s, OH);
13C NMR (100 MHz, CDCl3) d (ppm) 15.3, 22.3, 31.4,
34.0, 35.3, 38.4, 38.5, 38.7, 38.75, 39.1, 39.9, 46.6, 74.5,
78.7, 106.5, 119.3, 129.8, 130.7, 132.55, 167.4, 167.6,
214.9; MS (EI, 70 eV, 140 ꢁC): 374 (9, M+), 356 (18,
M+ꢀH2O), 316 (22, M+ꢀ(CH3)2CO), 317 (22.5), 223
(35.5, M+ꢀhydrindene unit), 220 (33), 172 (44), 163 (35),
149 (42), 137 (39), 133 (41), 131 (50), 91 (100).
H(14exo), J14,14¼12.8, J14,13¼2.8), 2.30 (s, 3H, CH3(12)),
2.35 (dt, 1H, H(1), J1,1¼12.4, J1,2¼J1,13b¼8.4), 2.52 (m,
1H, H(13b), J13b,13a¼12.5, J13b,3a¼8.8, J13b,1¼8.4, 5.8),
00 00
00 00
00 00
2.67 (m, 1H, H(3a), J3a,13b¼8.8, J3a,4¼3.7, J3a,3¼3.3, J3a,5
¼
2.6), 3.17 (ddd, 1H, H(13), J13,14¼3.0, 2.8, J13,13a¼2.9), 3.97
(dd, 1H, H(3), J3,2¼3.4, J3,3a¼3.3), 4.02 (dd, 1H, H(5a),
J5a,5¼5.8, J5a,13a¼3.1), 6.00 (dd, 1H, H(4), J4,5¼9.7, J4,3a
¼
3.7), 6.05 (ddd, 1H, H(5), J5,4¼9.7, J5,5a¼5.8, J5,3a¼2.6),
6.74 (d, 2H, H(9,11), J9,10¼J11,10¼7.9), 7.04 (t, 1H, H(10),
J10,9¼J10,11¼7.8); 13C NMR (150 MHz, CDCl3) d (ppm)
14.3, 18.45, 27.8, 28.3, 28.8, 31.8, 37.7, 39.05, 42.1, 47.1,
63.7, 77.1, 97.7, 113.1, 122.2, 124.8, 127.2, 129.6, 130.45,
135.6, 155.6; MS (EI, 70 eV, 110 ꢁC): m/z (%)¼326 (77,
M+); 308 (11, M+ꢀH2O); 269 (93, MꢀCH2COCH3), 250
(26), 235 (35), 177 (39), 159 (70), 91 (100); HRMS (EI,
70 eV, 110 ꢁC) calcd for C21H26O3: 326.1882, found:
326.1877. Significant NOESY crosspeaks: 13a/5a estab-
lishes the vicinal cis position, 1endo/CH3(2) and 1endo/
13a as well as OH/13a and OH/4 (visible in C6D6) confirm
the endo position of 13a and 5a, 14exo/13b as well as the
w-coupling 14endo/13a establish the R-configuration of
C(13).
4.20. 8-Methylene-2-oxabicyclo[2.2.2]octane-3,5-dione
(25)
(R)-6-Allyldihydropyran-2,4-dione 4 (50 mg, 0.32 mmol)
was dissolved in degassed acetic acid (5.5 mL).
3Mn(OAc)3$7H2O (259 mg, 0.96 mmol) and Cu(OAc)2$
H2O (97 mg, 0.49 mmol) were added, and the solution was
stirred at35 ꢁC for2.5 h. Itwas then diluted with ethyl acetate
(30 mL) and washed with satd aq NaHCO3 (4ꢂ15 mL). The
solvent was removed under reduced pressure, and the product
was obtained by crystallization from dichloromethane/pen-
tane (47%). Mp¼171–172 ꢁC (possibly by conversion to 2-
hydroxy-6-methylbenzoic acid (mp 171 ꢁC) via thermal
retro Diels–Alder reaction). [a]2D0 +12.9 (c 0.38, acetone).
IR (cmꢀ1) 2974, 2330, 1767, 1738, 1733, 1699, 1683, 1657,
1652, 1606. 1H NMR (400 MHz, CDCl3) d (ppm) 2.42 (dd,
Compound 26: [a]2D0 +18.0 (c 0.205, acetone). IR (cmꢀ1
film) 3502 (br), 2929, 1704, 1645. H NMR (600 MHz,
,
1
1H, H(6), J6,6¼19.2, J6,1w1.52), 2.58 (dq, 1H, H(7), J7,7
¼
CDCl3) d (ppm) 1.10 (d, 3H, CH3(2), JCH ¼ 6:8), 1.43
3;2
0
0
17.43, J7,1wJ7,1wJ7,1w1.77), 2.76 (dt, 1H, H(6), J6,6¼19.2,
(m, 1H, H(1endo), J1,1¼J1,2¼12.4, J1,13b¼6.0), 1.51 (s,
J6,1wJ6,7w3.28), 2.95 (m, 1H, H(7), J7,7¼17.43, J7,1w3.8,
3H, CH3(7)), 1.52 (m, 1H, H(14endo), J14,14¼13.3, J14,13a
¼
0
0
J7,6w3.3, J7,1wJ7,1w2.78), 4.05 (s, 1H, H(4)), 5.07 (m, 1H,
3.0, J14,13b¼0.6), 1.615 (m, 1H, H(13a), J13a,13b¼12.5,
J13a,5a¼3.4, J13a,13¼2.9), 2.01 (m, 1H, H(2), J2,1¼12.4,
H(1), J1,7wJ1,6w3.8, J1,7wJ1,6w1.8–1.5), 5.12 (m, 1H, H(10),
J1 ,1w2.28, J1 , w2.02), 5.23 (m, 1H, H(10), J1 ,1w2.28,
J2,1¼8.9, J2;CH ¼ 6:8, J2,3¼3.4), 2.219 (dd, 1H, H(14exo),
0
0
0
0
0
7
3
J1 ,7w2.52, J1 ,7<1.5); 13C NMR (100 MHz, CDCl3)
d (ppm) 33.45, 41.6, 67.6, 73.6, 116.7, 131.4, 166.6, 197.3;
MS (EI, 70 eV, 30 ꢁC) 152 (18, M+), 134 (8, M+ꢀH2O),
110 (53, M+ꢀCH2CO), 108 (42, M+ꢀCO2), 82 (100), 54
(82). Anal. Calcd for C8H8O3: C¼63.15%, H¼5.30; found:
C¼63.15%, H¼5.52%.
J14,14¼13.3, J14,13¼2.6), 2.22 (ddd, 1H, H(1exo), J1,1
¼
0
0
12.4, J1,2¼8.9, J1,13b¼7.8), 2.32 (ddd, 1H, H(9exo),
J9,9¼17.1, J9,10¼4.0, J¼1.1), 2.35 (m, 1H, H(13b), J13b,13a
¼
12.5, J13b,3a¼8.8, J13b,1¼7.8, J13b,1¼6.0), 2.46 (m, 1H,
H(10), J1 ,1w14.2, J1 ,2 ¼J1 ,10¼7.1, J1 ,3wJ1 ,3 ¼1), 2.55
0
0
0
0
0
0
0
0
0
(m, 1H, H(10), J1 ,1 ¼14.2, J1 ,2w6.8–7, J1 ,10¼5.6, J1 ,3
w
0
0
0
0
0
0
0
0
0
J1 ,3w1.3), 2.64 (dd, 1H, H(9endo), J9,9¼17.1, J9,10¼12.1),
2.62 (m, 1H, H(3a), J3a.13b¼8.8, J3a,4¼3.8, J3a,3¼3.3,
J3a,5¼2.6), 2.90 (m, 1H, H(13), J13,14¼3.0, J13,13a¼2.9,
J13,14¼2.6), 3.97 (dd, 1H, H(3), J3,2¼3.4, J3,3a¼3.3), 3.98
(dd, 1H, H(5a), J5a,5¼5.6, J5a,13a¼3.4), 4.48 (m, 1H,
4.21. (2R,3R,3aR,5aS,7S,13R,13aS,13bS)-10-Allyl-2,7-
dimethyl-1,2,3,3a,5a,9,10,13,13a,13b-decahydro-7,13-
methano-12H-pyrano[3,4-d]indeno[4,5-g]-1,3-oxacin-3-
ol (26) and (2R,3R,3aR,5aS,7S,13R,13aS,13bS)-2,7,12-
trimethyl-1,2,3,3a,5a,13,13a,13b-octahydro-7,13-meth-
anobenzo[d]indeno[4,5-g]-1,3-dioxacin-3-ol (27)
0
0
H(10), J10,9¼12.1, J10,1 ¼7.4, J10,9¼4.0, J10,1 ¼5.4), 5.162
(m, 1H, H(30), J3 .3 ¼2.0, J3 ,2 ¼9.9, J3 ,1wJ3 ,1w1.0), 5.167
0
0
0
0
0
0
0
0
(m, 1H, H(30), J3 .3 ¼2.0, J3 ,2 ¼17.5, J3 ,1wJ3 ,1w1.3), 5.82
0
0
0
0
0
0
0
0
(ddt, 1H, H(20), J2 ,3 ¼17.5, J2 ,3 ¼9.9, J2 ,1 ¼J2 ,1 ¼6.8),
6.01 (m, 1H, H(5), J5,4¼10.0, J5,5a¼5.6, J5,3a¼2.6), 6.07
(dd, 1H, H(4), J4,5¼10.0 J4,3a¼3.8); 13C NMR (150 MHz,
CDCl3) d (ppm) 14.05, 26.4, 27.2, 28.85, 30.9, 31.9, 37.4,
39.0, 39.3, 41.0, 47.1, 65.0, 74.7, 77.3, 100.5, 104.2,
119.0, 127.8, 131.7, 132.1, 165.9, 166.6; MS (EI, 70 eV,
130 ꢁC): m/z (%)¼372 (30, M+), 301 (75, M+ꢀC4H6OH),
223 (26), 181 (37.5), 163 (23), 155 (44), 91 (100); HRMS
(EI, 70 eV, 130 ꢁC) calcd for C22H26O5: 372.1937, found:
372.1928. Significant NOESY crosspeaks: 13a/5a estab-
lishes the vicinal cis position, 1endo/CH3(2) and 1endo/
13a as well as OH/13a and OH/5a (visible in C6D6) confirm
the endo position of 13a and 5a, 14exo/13b as well as the
w-coupling 14endo/13a establish the R-configuration of
C(13).
0
0
0
0
0
0
0
0
Compound 24 (38 mg, 98 mmol), 3Mn(OAc)3$7H2O
(79 mg, 0.29 mmol) and Cu(OAc)2$H2O (29 mg,
0.15 mmol) were stirred in degassed acetic acid (2 mL) at
35 ꢁC for 2.5 h. The solution was then diluted with ethyl ace-
tate, washed with satd aq NaHCO3 and dried over MgSO4.
The products were separated by flash chromatography on sil-
ica gel (petroleum ether/ethyl acetate 2:1). From these prod-
ucts the two main compounds 26 (7.3 mg, 20 mmol, 20%)
and 27 (5.5 mg, 17 mmol, 17%) could be isolated and char-
acterized as a colourless oil. Compound 27: [a]2D0 +25,0
(c 0.12, acetone). IR (cmꢀ1, film) 3503 (br), 3030, 2876,
1584, 1264. 1H NMR (600 MHz, CDCl3) d (ppm) 1.11
(d, 3H, CH3(2), JCH ¼ 6:9), 1.34 (td, 1H, H(1endo),
3;2
J1,1¼12.4, J1,2¼12.1, J1,13b¼5.8), 1.53 (dt, 1H, H(13a),
J13a,13b¼12.5, J13a,5a¼3.1, J13a,13¼2.9), w1.5 (br, 1H,