Jayanth et al.
reaction mixture was stirred at room temperature for 8 h. The
reaction mixture was then filtered through Celite and silica
gel and eluted with dichloromethane. The filtrate was con-
centrated, and the residue was purified on a silica gel column
using hexanes-ethyl acetate as eluent to afford the desired
products.
Products 3a-o were obtained according to this procedure.
Product yields of these reactions are listed in Table 1, and the
spectral data of representative products are listed below. All
of these products decomposed during melting point determi-
nation, likely undergoing retro Diels-Alder reactions, at
Procedure for Deoxyaromatization of 3 to Benzo[b]-
triphenylenes (8). A round-bottom sidearm flask (25 mL)
containing 3 (0.500 mmol) was evacuated and purged with
nitrogen gas three times. Dichloromethane (2.0 mL) and BF
OEt (0.090 mL, 0.750 mmol) were added. The reaction
mixture was stirred at room temperature for 1 h. The reaction
mixture was then poured into a saturated aqueous NaHCO
solution and extracted with dichloromethane. The organic
layer was washed with brine, dried (MgSO ), and concentrated
3
‚
2
3
4
under reduced pressure. The residue was recrystallized from
a mixture of dichloromethane and hexanes to afford the desired
products.
Products 8a-f were obtained according to this procedure.
Product yields of these reactions are listed in Tables 2, and
the spectral data of representative products are listed below.
temperature >130 °C.
(
2R*,15S*)-23-Oxahexacyclo[14.6.1.02,15.03,8.0 .017,22]-
9,14
1
tricosa-3(8),4,6,9(14),10,12,17,19,21-nonaene (3a). H NMR
(
600 MHz, CDCl
H), 7.32-7.25 (m, 6 H), 5.40 (s, 2 H), 3.42 (s, 2 H). C NMR
150 MHz, CDCl ): δ 145.7, 135.0, 131.8, 129.9, 128.0, 127.0,
3
): δ 7.94 (d, J ) 6.6 Hz, 2 H), 7.44-7.41 (m,
13
4
2
,3,6,7-Tetramethyldibenzo[5,6:7,8]anthra[2,3-d][1,3]-
(
3
1
dioxole (8c). Colorless needles, mp 274-275 °C. H NMR (600
1
26.9, 122.7, 119.2, 90.3, 43.9. HRMS calcd for C22
96.1201, found 296.1213.
16
H O
MHz, d
6
-DMSO): δ 9.05 (s, 2 H), 8.54 (s, 2 H), 8.43 (s, 2 H),
2
13
7
.48 (s, 2 H), 6.16 (s, 2 H), 2.48 (s, 12 H). C NMR (150 MHz,
(
2R*,15S*)Pentacyclo[14.2.1.02,15.03,8.09,14]nonadeca-3(8),-
1
d
6
-DMSO): δ 147.7, 136.1, 135.8, 129.3, 127.3, 127.2, 126.3,
4
7
2
3
,6,9(14),10,12-hexaene (3b). H NMR (600 MHz, CDCl ): δ
1
24.0, 123.9, 120.6, 102.9, 101.3,19.8, 19.7. HRMS calcd for
378.1620, found 378.1618.
,2,3,6,7,8-Hexahydrodiindeno[5′,6′:5,6:5′,6′:7,8]anthra-
2,3-d][1,3]dioxole (8d). Colorless needles, mp 269-270 °C.
.87 (d, J ) 6.6 Hz, 2 H), 7.26-7.21 (m, 6 H), 3.24 (s, 2 H),
.41 (s, 2 H), 1.73-1.72 (m, 2 H), 1.66-1.65(m, 2 H), 1.44 (d,
27 22 2
C H O
1
1
3
J ) 12.0 Hz, 1 H), 1.06 (d, J ) 12.0 Hz, 1H). C NMR (150
[
MHz, CDCl
3
): δ 137.6, 131.3, 130.1, 127.6, 126.2, 122.0, 49.5,
5.8, 33.2, 30.2. HRMS calcd for C19 18 246.1409, found
46.1404.
2R*,15S*)Pentacyclo[14.2.1.02,15.03,8.09,14]nonadeca-3(8),-
1
H NMR (600 MHz, CDCl
s, 2 H), 7.28 (s, 2 H), 6.05 (s, 2 H), 3.12 (m, 8 H), 2.19 (m, 4
H). C NMR (150 MHz, CDCl
28.9, 128.3, 127.6, 120.6, 118.5, 118.2, 103.2, 100.9, 33.0, 25.8.
HRMS calcd for C29 402.1620, found 402.1618.
3
): δ 8.81 (s, 2 H), 8.53 (s, 2 H), 8.40
4
2
H
(
13
3
): δ 147.8, 143.9, 143.6, 129.4,
(
1
1
4
,6,9(14),10,12,17-heptaene (3c). H NMR (600 MHz, CD-
22 2
H O
Cl
3
): δ 7.95 (d, J ) 12.0 Hz, 2 H), 7.37 (d, J ) 8.4 Hz, 2 H),
Diels-Alder Cycloaddition of in Situ Generated
Isobenzofuran from 3g with Diethyl Acetylenedicar-
boxylate. A round-bottom sidearm flask (25 mL) containing
7
.30-7.27 (m, 4 H), 6.41 (s, 2 H), 3.11 (s, 2 H), 3.04 (s, 2 H),
1
.44 (d, J ) 12.0 Hz, 1 H), 1.21 (d, J ) 12.0 Hz, 1 H). 13C NMR
(
3
150 MHz, CDCl ): δ 137.8, 137.6, 131.8, 130.2, 127.6, 126.2,
3
g (0.500 mmol, 0.176 g) and diethyl acetylenedicarboxylate
1
22.3, 55.4, 42.7, 41.2. HRMS calcd for C19
H16 244.1252, found
(
1.00 mmol, 0.170 g) in dry toluene was refluxed for 24 h under
2
44.1255.
nitrogen atmosphere. The reaction mixture was cooled and
concentrated, and the residue was purified on a silica gel
column using hexanes-ethyl acetate as eluent to give 9 in 69%
yield (0.099 g) and 10 in 98% yield (0.115 g).
Ethyl (2R*,15S*)-23-Azahexacyclo[14.6.1.02,15.03,8.09,14.-
01
7,22
]tricosa-3(8),4,6,9(14),10,12,17(22),18,20-nonaene-23-
1
carboxylate (3f). H NMR (600 MHz, CDCl
3
): δ 7.88 (d, J )
7
.8 Hz, 2 H), 7.45 (d, J ) 7.2 Hz, 4 H), 7.31-7.21 (m, 6 H),
.27 (bd, 2 H), 3.66 (bd, 2 H), 3.60 (s, 2 H), 0.84 (s, 3 H). 13
): δ 155.3, 145.3, 134.3, 131.6, 130.2,
28.1, 127.5, 126.5, 122.5, 119.8, 71.8, 60.9, 44.1, 14.1. HRMS
calcd for C25 367.1572, found 367.1569.
2R*,15S*)-5,6,11,12-Tetramethyl-23-oxahexacyclo-
5
C
NMR (150 MHz, CDCl
3
Acknowledgment. We thank the National Science
Council of the Republic of China (NSC 92-2113-M-007-
044) for support of this research.
1
H
21N0
2
(
2
,15 3,8 9,14 17,22
[
14.6.1.0 .0 .0 .0
]tricosa-3(8),4,6,9(14),10,12,17(22),-
8,20-nonaene (3g). H NMR (600 MHz, CDCl ): δ 7.72 (s, 2
H), 7.48 (d, J ) 8.4 Hz, 2 H), 7.29 (d, J ) 8.4 Hz, 2 H), 7.20 (s,
Supporting Information Available: Spectral data for
1
1
3
1
compounds 3d, 3e, 3h-o, 8a, 8b, 8e, 8f, 9, and 10 and H
NMR spectra for all compounds 3a-o, 8a-f, 9, and 10. This
material is available free of charge via the Internet at
http://pubs.acs.org.
1
3
2
H), 5.41 (s, 2 H), 3.55 (s, 2 H), 2.36 (s, 12 H). C NMR (150
MHz, CDCl ): δ 145.9, 136.0, 135.0, 132.2, 131.0, 129.6, 126.8,
23.5, 119.1, 90.1, 43.4, 19.7, 19.5. HRMS calcd for C26
52.1827, found 352.1831.
3
1
3
24
H O
JO048702K
8450 J. Org. Chem., Vol. 69, No. 24, 2004