The synthesis of naphthosultine and benzodisultines and their pyrolysis with dienophiles: Studies on o-naphthoquinodimethane and bis-o-quinodimethane

Article abstract of DOI:10.1002/jccs.200200013

Sealed tube reactions of the naphthosultine 8 with a series of electron-deficient dienophiles (fumaronitrile, N-phenylmaleimide, dimethyl fumarate, and dimethyl acetylenedicarboxylate) in toluene at 180 °C gave corresponding 1:1 cycloadducts 11-14 in various amounts along with rearranged naphthosulfolene 7 in 67-95% yields. The reaction of 1,2,4,5-tetra(bromomethyl) benzene with Rongalite (sodium formaldehyde sulfoxylate) and tetrabuty lammonium bromide in DMF gave benzodisultines 17 and 18 in a combined yield of 56%. Sealed tube reactions of benzodisultines 17 and 18 with a series of dienophiles in xylene at 200 °C gave corresponding 1:1 and 1:2 cycloadducts 20-27. The results suggested that thermal extrusion of sulfur dioxide from these sultines led to either o-naphthoquinodimethane 6 (from 8) or bis-o-quinodimethane 19 (from 17 and 18); subsequent trapping of these reactive intermediates by dienophiles and SO₂ gave various 1:1 and 1:2 Diels-Alder adducts in modest to excellent yields.

Full text of DOI:10.1002/jccs.200200013

JournaloftheChineseChemicalSociety, 2002, 49, 77-82
77
The Synthesis of Naphthosultine and Benzodisultines and their Pyrolysis
with Dienophiles: Studies on o-Naphthoquinodimethane and
Bis-o-quinodimethane
An-Tai Wu (
), Wen-Dar Liu (
) and Wen-Sheng Chung* (
)
DepartmentofAppliedChemistry,NationalChiaoTungUniversity,Hsinchu,Taiwan30050,R.O.C.
Sealed tube re ac tions of the naphthosultine 8 with a se ries of elec tron-deficient dienophiles (fumaro-
nitrile, N-phenylmaleimide, dimethyl fumarate, and dimethyl acetylenedicarboxylate) in to lu ene at 180 °C
gavecorresponding1:1cycloadducts11-14 in var i ous amounts along with re ar ranged naphthosulfolene 7 in
67-95% yields. The re ac tion of 1,2,4,5-tetra(bromomethyl)ben zene with Rongalite (so dium form aldehyde
sulfoxylate) and tetrabutylammonium bro mide in DMF gave benzodisultines 17 and18 in a com bined yield of
56%. Sealed tube re ac tions of benzodisultines 17 and 18 with a se ries of dienophiles in xylene at 200 C gave
corresponding1:1and1:2cycloadducts20-27.Theresultssuggestedthatthermalextrusionofsulfurdioxide
from these sultines led to ei ther o-naphthoquinodimethane 6 (from 8) or bis-o-quinodimethane 19 (from 17
and 18);subsequenttrappingofthesereactiveintermediatesbydienophilesandSO2 gave var i ous 1:1 and 1:2
Diels-Alderadductsinmodesttoexcellentyields.
INTRODUCTION
Much at ten tion has been fo cused on the syn the sis of
Thus, finding an easy, high-yield method for generating
naphthoquinodimethane 6 and a fur ther ex ten sion to bis-o-
QDMareofparticularinterests.Recentlywedescribed7 the
generationofaseriesofheteroaromatico-QDMs, by ther mal
extrusionofSO2 fromcorrespondingsultines, andexplored
their ap pli ca tion in Diels-Alder re ac tions with dienophiles
including[60]fullerene.Theadvantagesofusingsultinesare
(1) their thermolysis oc curs at a much lower tem per a ture than
thatofcorrespondingsulfolenes,7-8 and (2) they are usu ally
sta ble above room tem per a ture. We re port here our work on
the syn the sis of naphthosultine 8 and benzodisultines 17 and
18 and their applications in Diels-Alder reactions with
alkenes and al kynes.
polycyclic com pounds us ingo-quinodimethane (o-QDM) 1
anditsanalogues, andnumerousmethodsforthegeneration
of the o-QDMintermediateshavebeendeveloped.1 Among
them are ring-openings of benzocyclobutenes2 2,1,4-elimi-
na tion of , -disubstituted o-xylenes 3,3 andvarious“extru-
sion” re ac tions in volv ing loss of a small mol e cule.1 For ex-
ample, lossesofN2 from diazene4 4or SO2 from sulfolene1,5
have been shown to lead to the o-QDMintermediates.
5
N
N
X
Y
4
1
2
3
RESULTS AND DISCUSSION
Naphthosultine 8 is readily syn the sized in three steps
from 2,3-naphthalene-dicarboxylate with an over all yield of
42%, as shown in Scheme I. The 2,3-di(bromomethyl)naph-
thalene10 was ob tained in 70% yield by bromination of the
naphthodiol 9, and the diol was ob tained in 96% yield from a
lith ium alu mi num hy dride re duc tion of the dicarboxylate.
Sub se quent treat ment of the dibromide 10 with Rongalite8
(sodium formaldehyde sulfoxylate) and tetrabutyl ammo-
nium bro mide (TBAB) in DMF gave the de sired sultine 8 in
63%. Sealed tube re ac tions of the naphthosultine 8with out
and with 1.2 equiv. of var i ous elec tron-deficient dienophiles
(fumaronitrile, N-phenylmaleimide, dimethyl fumarate, and
SO
SO
2
2
5
6
7
In a pi o neer ing work by Cava and co work ers,6 a the
naphthoanalogueofo-QDM 6 was gen er ated us ing SO2 ex-
tru sion from sulfolene 7;however,areactiontemperatureof
300 C was re quired! The naphthoquinodimethane 6 was
later re ported by Wirz et. al. us ing a diazene-precursor,6b but
the diazene com pound was un sta ble and had to be kept un der
-40 C.Furthermore,anintractablemixtureofproductswas
ob tained in deaerated so lu tion of the diazene com pound.

78 J. Chin. Chem. Soc., Vol. 49, No. 1, 2002
Wu et al.
Scheme I
trapped ei ther by SO2 or by dienophiles. Con se quently, higher
yields of the Diels-Alder ad ducts 11-14 were ob tained if ex-
cess amounts of dienophiles or stron ger dienophiles (such as
N-phenylmaleimide vs. dimethyl fumarate or dimethyl ace-
tyl enedicarboxylate) were used.
CO CH
2
3
CH OH
LiAlH
4
2
THF
96%
CO CH
2
3
CH OH
2
9
Benzodisultines were syn the sized in two steps from
1,2,4,5-tetramethylbenzene (see Scheme III). Standard
bromination of 1,2,4,5-tetramethylbenzene by NBS in chlo-
ro form gave 1,2,4,5-tetra(bromomethyl)ben zene 16 in 60%
yield. Subsequent treatment of tetrabromide 16 with 5.5
equiv. of Rongalite gave the de sired benzodisultines as a mix-
ture of diastereomers 17 and 18 in 56% yield. Due to the co-
ex is tence of two chiral cen ters and two regio po si tions of
disultines, at least four diastereomeric prod ucts are ex pected.
1H NMR Spec tra of the mix tures of disultines were quite
com plex but their struc tures could be rec og nized by the char-
acteristicABquartetpatternsofthediastereotopicmethylene
pro tons of each sultine ring.7 We used the mix ture of benzo-
disultines for all the sealed tube trap ping ex per i ments shown
in Scheme IV. Al though benzosultine was re ac tive at ca. 100
C,8 the re ac tion of benzodisultines at this tem per a ture was
slug gish; there fore, all the thermolysis and trap ping ex per i-
ments were car ried out at 200 Cfor 10 min.
PPh Br /
3
2
70%
CH Cl
2
2
O
CH Br
2
Rongalite
S
O
TBAB
DMF
63%
CH Br
2
8
10
dimethyl acetylenedicarboxylate) in to lu ene at 180 C gave
the re ar ranged naphthosulfolene 7 andcorresponding1:1
cycloadducts 11-14 in 67-95% yields (see Scheme II). In the
ab sence of quencher, naphthosultine 8 underwentathermal
re ar range ment to give the naphthosulfolene 7 in 84% yield.
In con trast,7was re ported6a toundergothermalextrusionof
SO2 in a boiling diethyl phthalate solution (300 C) and
formed the naphtho[b]cyclobutene 15 in 60% yield. The con-
com i tant for ma tion of Diels-Alder ad ducts 11-14 and sul-
folene 7inallreactionsimpliesthatreactiveintermediate
naphthoquinodimethane 6 was prob a bly formed but was then
Scheme III
Scheme II Where NPM is N-phenylmaleimide,
DMAD is dimethyl acet y lene-
dicarboxylate, and DMF is dimethyl
fumarate
NBS/CHCl3
Rongalite
Br
Br
Br
Br
reflux
60%
TBAB/DMF
56%
16
O
O
S
O
+
CN
O
S
S
O
S
O
SO
2
O
O
CN
11 (78%)
+ 7 (15%)
7 (84%)
18
17
mixtures
no quencher
fumaronitrile
Since there are two sultine rings in a benzodisultine ( 17
or 18), in prin ci ple, these rings can be cleaved by a si mul ta-
neousorastepwisesequentialmechanism.9 It is thus not sur-
pris ing for us to see two types of prod ucts formed in the
sealed tube re ac tion of benzodisultine with a se ries of elec-
tron-deficient dienophiles (Scheme IV). When tetracyano-
ethylene (TCE) was used as dienophile, only dou ble Diels-
Alder adduct23 was formed in 63% yield; the yield is sim i lar
tothatreportedbyVogel et al.9 aforthesequentialtrappingof
7-oxa[2.2.1]hericene 28. The ra tio for the two rate con stants
k1 and k2 of the two suc ces sive Diels-Alder re ac tions of 28
with TCE was found to be around 21. Fur ther more, the ra tios
of k1/k2 for the reaction of 2,3,5,6-tetramethylidenebicy-
O
O
toluene
NPM
8
N
Ph
o
180
-SO
C
2
12 (90%)
+ 7 (5%)
6
DMAD
DMF
CO CH
2
3
CO CH
2
3
CO CH
CO CH
3
3
2
3
14 (47%)
+ 7 (20%)
13 (54%)
+ 7 (26%)

Studies on Bis-o-quinodimethanes
J. Chin. Chem. Soc., Vol. 49, No. 1, 2002 79
Scheme IV Wheretheabbreviationsarethesameas
those used in Scheme II, DEF is di ethyl
ported.Theresultssuggestedthatthermalextrusionofsulfur
di ox ide from these sultines led to re ac tive o-naphtho quino-
dimethane 6 and bis-o-QDM 19,subsequenttrappingofthese
reactiveintermediatesbydienophilesorSO2 gavevarious1:1
and 1:2 Diels-Alder ad ducts in mod est to ex cel lent yields.
The bis-o-QDM is syn thet i cally use ful for polycyclic com-
poundswithdifferentfunctionalities.
fumarate, and TCE is tetracyanoethylene
O
O
NPh
PhN
CN
CN
O2S
O
O
O
21 (14%)
22 (16%)
20 (41%)
+
NPh
O2S
NPM
fumaronitrile
EXPERIMENTAL SECTION
O
General
CN
NC
NC
xylenes
TCE
CN
CN
CN
17 and
Melting points were de ter mined on a Yanaca MP-500D
meltingpointapparatusandareuncorrected.1H NMR spec tra
were re corded at 300 MHz NMR, 13C and DEPT were re-
corded at 75.4 MHz, and the chem i cal shifts are re ported in
parts per mil lion ( ) in val ues rel a tive to CDCl3 ( = 7.25 for
pro ton and 77.00 ppm for car bon) or tetramethylsilane as in-
ternal standard. Cou pling con stants are re ported in hertz
(Hz). Mass spec tra were re corded on a VG-Trio 2000 spec-
trometer. High-resolution mass was recorded on a Jouel
JMS-HX110 or a JMS-SX/SX 102A spec trom e ter of the in-
stru ment cen ter of Na tional Tsing-Hua and Na tional Chung-
Hsin Uni ver sity. C, H, N com bus tion anal y ses were de ter-
minedonaHeraeusanalyzerandallanalyzedcompoundsare
within 0.4%ofthetheoreticalvalueunlessotherwiseindi-
cated. Columnchromatographywasperformedonsilicagel
of 70-230 or 230-400 mesh from E. Merck. The prep a ra tion
of1,2,4,5-tetra(bromomethyl)benzene 16 fol lowed a lit er a-
tureprocedure. 11
200 oC
NC
NC
18
19
23 (63%)
DMAD
DEF
MeO2C
CO2Me
CO2Me
EtO2C
CO2Et
MeO2C
+
EtO2C
CO2Et
24 (22%)
25 (49%)
26 (40%)
27 (42%)
+
CO2Me
CO2Me
CO2Et
CO2Et
O2S
O2S
clo[2.2.1]heptane with a se ries of dienophiles are ca. 250-
376,9a which were ra tio nal ized by Vogel to be due to the great
differencesinexothermicitybetweentwosuccessiveDiels-
Alder re ac tions. The py rol y sis of benzodisultine with other
dienophiles(includingN-phenylmaleimide, diethylfumarate
and dimethyl acetylenedicarboxylate) gave both 1:1 and 1:2
Diels-Alder ad ducts in about 1~2 ra tio. Al though there are
competitivetrappingsofSO2 and dienophile in both ends of
the benzodisultine, the above re sults in di cated that they ei-
ther re act in de pend ently, or they do not in ter fere with each
other much; there fore, two suc ces sive Diels-Alder re ac tion
prod ucts are sim i lar in yields. It is im por tant to note that due
to the ex is tence of a sulfolene group in ad ducts (20, 22, 25,
and 27), one can still add in an other func tion al ity through a
sec ond stage Diels-Alder re ac tion.10 Thus, benzodisultine is
use ful for the syn the sis of multifunctional polycyclic com-
pounds.
3-(Hydroxymethyl)-2-naphthyl methanol 9
To a stirred so lu tion of LiAlH4 (0.89 g, 22.5 mmol) in
THF un der N2 at 0 C was added dimethyl 2,3-naphthalene-
dicarboxylate (1.00 g, 4.10 mmol). The so lu tion was stirred
for 30 min, and then acid i fied with 30% H2SO4. The pre cip i-
tatewasfilteredoffandthefiltratewasextractedwithCH2Cl2
(2 25 mL). The so lu tion was con cen trated un der re duced
pressureandtheresiduewaspurifiedbycolumnchromatog-
raphy(SiO2, EtOAc/hex ane, 1:3) to give a white solid9 (0.74
1
g, 96%): mp 160-161 C; H NMR (300 MHz, CDCl3)
7.82-7.85 (m, 4H), 7.48-7.52 (m, 2H), 4.91 (s, 4H), 2.96 (s,
2H); 13C NMR (75 MHz, CDCl3) 136.94 (Cq), 133.16 (Cq),
128.81 (CH), 127.68 (CH), 126.51 (CH), 64.62 (CH2); MS
(EI) 188 (M+, 54), 170 (100), 141 (83); HRMS (EI) calcd for
C12H12O2: 188.0838, found 188.0846.
CONCLUSION
Naphthosultine 8 and benzodisultines (17 and 18) were
readilysynthesizedandtheirapplicationinDiels-Alderreac-
tions with a se ries of elec tron-deficient dienophiles are re-
2,3-Di(bromomethyl)naphthalene106a
Toastirredsolutionof9 (1.00 g, 5.32 mmol) in CH2Cl2

80 J. Chin. Chem. Soc., Vol. 49, No. 1, 2002
Wu et al.
(15 mL) was added PPh3Br2 (0.82 g, 2.54 mmol). The mix ture
was stirred at room temperature. After 10 h, a saturated
NaHCO3 so lu tion (20 mL) was added to the mix ture and the
aque ous phase was ex tracted with CH2Cl2 (2 25 mL). The
combinedorganicextractsweredried(MgSO4) and then con-
centratedunderreducedpressure. Theresiduewaspurified
bycolumnchromatography(SiO2, EtOAc/hex ane, 1:3) to
nitrile, 78% of 11 (41.6 mg) and 15% of 7 (7.5 mg); N-
phenylmaleimide, 90% of12 (68 mg) and 5% of 7 (2.5 mg);
dimethyl acetylenedicarboxylate, 54% of 13 (37 mg) and
26% of7 (13 mg); and dimethyl fumarate, 47% of 14 (32 mg)
and 20% of 7 (10 mg).
2,3-Dihydro-1H-2 6-naphtho[2,3-c]thiophene-2,2-dione
give a white solid 10 (0.46 g, 70%): mp 116-118 C; 7.85
(s, 2H), 7.82-7.77 (m, 2H), 7.52-7.48 (m, 2H), 4.88 (s, 4H);
(naphthosulfolene) 7
H
A white solid; mp 254-255 C (lit.6 a 254-256 C);
H
133.76 (Cq), 133.29 (Cq), 130.79 (CH), 127.75 (CH),
7.80-7.84 (m, 4H), 7.26-7.55 (m, 2H), 4.52 (s, 4H); C 133.06
(Cq), 128.90 (Cq), 127.73 (CH), 126.97 (CH), 125.36 (CH),
56.51 (CH2); MS (EI) 218 (M+, 22), 154 (100); HRMS (EI)
calcd for C12H10O2S: 218.0402, found 218.0403. Anal. Calcd
for C12H10O2S: C, 66.03; H, 4.62. Found: C, 65.72; H, 4.85.
C
127.24 (CH), 31.07 (CH2); MS (EI) 316 (M+, 9), 314 (25),
312 (13), 235 (100), 233 (91), 152 (39), 154 (94), 155 (13);
HRMS (EI) calcd for C12H1079Br2 311.9149, found 311.9153.
Anal. Calcd for C12H10Br2: C, 45.90; H, 3.21. Found: C,
45.79; H, 3.46.
1,2,3,4-Tetrahydro-2,3-anthracenedicarbonitrile 11
3,4-Dihydro-1H-3I4-naphtho[2,3-d][1,2]oxathiin-3-one
(naphthosultine) 8
A white solid; mp 198-200 C;
7.30-7.80 (m, 6H),
H
3.20-3.60 (m, 6H); C 132.60 (Cq), 128.20 (Cq), 127.68 (CH),
127.29 (CH), 126.41 (CH), 118.57 (Cq), 30.87 (CH2), 29.08
(CH); MS (EI) m/z 232 (M+, 100), 154 (47); HRMS calcd for
C16H12N2 232.1560, found 232.1594.
A so lu tion of 10 (0.5 g, 1.6 mmol), so dium form al de-
hyde sulfoxylate (Rongalite) (0.78 g, 5.08 mmol) and tetra-
butylammonium bro mide (TBAB) (0.82 g, 2.54 mmol) in
DMF (10 mL) was stirred at rt for 3 h. The mix ture was di-
luted with H2O (10 mL) and extracted three times with
CH2Cl2. The or ganic layer was dried over MgSO4, and then
concentratedunderreducedpressure. Theresiduewaspuri-
fiedbycolumnchromatography(SiO2, EtOAc/hex ane, 1:3)
2-Phenyl-2,3,3a,4,11,11a-hexahydro-1H-naphtho[2,3-f]-
isoindole-1,3-dione 12
A white solid; mp 231-232 C (lit.6 a 230-233 C);
H
6.60-7.70 (m, 11H), 3.31-3.52 (m, 4H), 3.00-3.12 (m, 2H);
C
to give a white solid 8 (0.22 g, 63%): mp 167-169 C;
178.43 (Cq), 132.85 (Cq), 132.78 (Cq), 131.54 (Cq), 128.94
(CH), 128.5 (CH), 127.43 (CH), 126.38 (CH), 126.25 (CH),
125.76 (CH), 40.25 (CH3), 30.1 (CH2); MS (EI) m/z 327 (M+,
93), 179 (100); HRMS (EI) calcd for C22H17O2N 327.1260
found 327.1255.
H
7.86-7.80 (m, 4H), 7.57-7.53 (m, 2H), 5.52, 5.15 (ABq, J =
13.3 Hz, 2H), 4.69, 3.77 (A B q, J = 15.2 Hz, 2H); C 133.13
(Cq), 132.38 (Cq), 131.67 (Cq), 128.61 (CH), 127.73 (CH),
127.54 (CH), 126.77 (CH), 126.69 (CH), 125.04 (CH),
124.51 (Cq), 64.05 (CH2), 58.41 (CH2); MS (EI) 218 (M+, 6),
154 (100), 149 (11), 139 (10); HRMS (EI) calcd for C12H10O2S
218.0402, found 218.0397. Anal. Calcd for C12H10O2S: C,
66.03; H, 4.62. Found: C, 65.94; H, 4.98.
Dimethyl 1,4-dihydro-2,3-anthracenedicarboxylate 13
A white solid; mp 132-134 C;
7.43-7.90 (m, 6H),
H
3.90 (s, 4H), 3.85 (s, 6H); C 168.10 (Cq), 133.82 (Cq), 132.40
(Cq), 130.42 (Cq), 127.21 (CH), 126.17 (CH), 125.70 (CH),
52.43 (CH3), 31.73 (CH2); HRMS (EI) calcd for C18H16O4
296.1049, found 296.1048. Anal. Calcd for C18H16O4: C,
72.96; H, 5.44. Found: C, 72.78; H, 5.50.
General Procedure for the Trapping Experiments of
Naphthosultine 8 with Dienophiles such as Fumaronitrile,
N-Phenylmaleimide, Dimethyl Acetylene-Dicarboxylate,
and Dimethyl Fumarate
A so lu tion of naphthosultine 8 (50 mg, 0.23 mmol),
with or with out re spec tive dienophiles (0.28 mmol), in to lu-
ene (3 mL) was heated at 180 C in a sealed tube un der N2 for
4 h. The sol vent was evap o rated un der vac uum, and the res i-
due was sub jected to sil ica gel chro ma tog ra phy us ing hex-
ane/ethyl ac e tate (3:1) as the eluent. Naphthosulfolene 7 was
ob tained in 84% yield (no quencher). For the trap ping of
naphthoquinodimethane 6, the re spec tive yields are: fumaro-
Dimethyl 1,2,3,4-tetrahydro-2,3-anthracenedicarboxylate
14
A white solid; mp 114-115 C; H 7.36-7.60 (m, 6H),
3.69 (s, 6H), 3.60-3.20 (m, 6H); C 173.34 (Cq), 132.41 (Cq),
132.22 (Cq), 127.10 (CH), 127.06 (CH), 125.35 (CH), 52.03
(CH3), 40.80 (CH), 29.85 (CH2); MS (EI) m/z 298 (M+, 25),
238 (59), 459 (80), 180 (18), 179 (100); HRMS (EI) calcd for
C18H18O4 298.1205, found 298.1207.

Studies on Bis-o-quinodimethanes
J. Chin. Chem. Soc., Vol. 49, No. 1, 2002 81
1,2,4,5-Tetra(bromomethyl)ben zene 16
4H), 3.02-2.96 (m, 4H); c 178.27 (Cq), 134.22 (Cq), 131.40
(Cq), 128.89 (CH), 128.47 (CH), 127.40 (CH), 126.22 (CH),
40.17 (CH), 29.42 (CH2); MS (EI) m/z 476 (M+, 71), 328
(100), 179 (51), 165 (51).
A white solid;11 mp 150-152 C; H 7.38 (s, 2H), 4.60 (s,
8H); C 137.58 (Cq), 133.58 (CH), 28.66 (CH2).
4,6,7,9-Tetrahydro-1H,3H-3 4,7 4-[1,2]oxathiino[5 ,4 :4,5]-
benzo[d][1,2]oxathiine-3,7-diones 17 and 18
7-Phenyl-1,2,3,5,5a,6,7,8,8a,9-decahydro-2 6-thieno-
[3 ,4 :4,5]benzo[f]isoindole-2,2,6,8-tetraone 22
Asolutionof16 (1.0 g, 2.22 mmol), Rongalite (1.71 g,
11.10 mmol) and TBAB (0.36 g, 1.12 mmol) in DMF (10 mL)
was stirred at rt for 6 h. The mix ture was di luted with H2O (10
mL) and ex tracted three times with CH2Cl2. The or ganic layer
was dried over MgSO4. Evap o ra tion of the sol vent and the
residuewaspurifiedbycolumnchromatography(EtOAc/
hex ane, 1:3) to give a mix ture of 17 and 18 (0.32 g, 56%). 17
and 18: H 7.11-7.17 (m, 4H), 4.97, 5.30 (A B q, J = 13.8 Hz,
8H), 4.40, 4.30 (ABq, J= 15.0 Hz, 4H), 3.62, 3.56 (A B q, J =
14% yield, a white solid; mp 240-241 C; H 6.79-7.33
(m, 7H), 4.25 (s, 4H), 2.89-3.44 (m, 6H); c 178.03 (Cq),
136.12 (Cq), 131.42 (Cq), 130.39 (Cq), 129.15 (CH), 128.78
(CH), 126.20 (CH), 125.56 (CH), 56.66 (CH2), 39.86 (CH),
29.80 (CH2); MS (EI) m/z 367 (M+, 10), 335 (100), 179 (21).
1,2,3,4,5,6,7,8-octahydroanthracene-2,2,3,3,6,6,7,7-otacar-
bonitrile 23
15.0 Hz, 4H);
133.32 (Cq), 132.83 (Cq), 131.54 (CH),
63% yield, a brown solid; mp 270 C (lit.9a > 200 C);
1HNMR(300MHz,acetone-d6) H 7.48 (s, 2H), 4.25 (s, 8H);
13CNMR(75MHz,acetone-d6) C 130.76 (CH), 127.58 (Cq),
111.78 (Cq), 39.71 (Cq), 34.66 (CH2); MS (EI) m/z 386 (M+,
8), 258 (100). HRMS calcd for C22H10N8 386.1031, found
386.1004.
C
131.02 (CH), 127.14 (CH), 126.74 (Cq), 126.12 (Cq), 125.54
(Cq), 123.06 (CH), 122.80 (CH), 62.40 (CH2), 62.32 (CH2),
56.31 (CH2), 55.64 (CH2); HRMS (EI) calcd for C10H10O4S2
258.0021, found 258.0019.
General Procedure for the Trapping Experiments of
Benzodisultines 17 and 18 with Dienophiles such as
Fumaronitrile, N-Phenylmaleimide, Tetracyanoethylene,
Dimethyl Acetylenedicarboxylate, and Diethyl Fumarate
A so lu tion mix ture of benzodisultines17 and 18 (40
mg, 0.16 mmol), with re spec tive dienophiles (0.93 mmol), in
xylenes (3 mL) was heated at 200 C in a sealed tube un der N2
for 10 min. The sol vent was evap o rated un der vac uum, and
theresiduewassubjectedtosilicagelchromatographyusing
hex ane/ethyl ac e tate (from 2:1 to 8:1) as the eluent. Re spec-
tive yields for the trap ping ex per i ments with var i ous dieno-
philes are sum ma rized in Scheme IV.
Tetramethyl 1,4,5,8-tetrahydro-2,3,6,7-anthracenetetra-
car boxylate 24
22% yield, a white solid; mp 206-208 C; 1H NMR (300
MHz, CDCl3) H 6.97 (s, 2H), 3.83 (s, 12H), 3.68 (s, 8H);13C
NMR (75 MHz, CDCl3) c 168.06 (Cq), 133.29 (Cq), 130.13
(Cq), 127.20 (CH), 52.38 (CH3), 31.04 (CH2); MS (EI) m/z
414 (M+, 7), 382 (100), 323 (23), 263 (17), 178 (41).
Dimethyl 2,2-dioxo-2,3,5,8-tetrahydro-1H-2 6-naphtho-
[2,3-c]t hiophene-6,7-dicarboxylate 25
49% yield, a white solid, mp 210-211 C;
7.13 (s,
H
2H), 4.33 (s, 4H), 3.84 (s, 6H), 3.72 (s, 4H); c 167.65 (Cq),
132.85 (Cq), 132.63 (Cq), 129.79 (Cq), 125.44 (CH), 56.55
(CH2), 52.45 (CH3), 31.24 (CH2); MS (EI) m/z 336 (M+, 8),
304 (100), 277 (42), 239 (82), 212 (52), 181 (45), 154 (65).
HRMS calcd for C16H16O6S 336.0668, found 336.0613.
6
2,2-Dioxo-2,3,5,6,7,8-hexahydro-1H-2 -naphtho[2,3-c]-
thiophene-6,7-dicarbonitrile 20
41% yield; a white solid, mp 228-229 C;
7.14 (s,
H
2H), 4.34 (s, 4H), 3.46-3.33 (m, 4H), 3.21-3.15 (m, 2H); c
131.11 (Cq), 130.82 (Cq), 126.71 (CH), 118.00 (Cq), 56.46
(CH2), 29.92 (CH2), 28.02 (CH); MS (EI) m/z 272 (M+, 2),
208 (100), 130 (15), 117 (22). HRMS calcd for C 14H12N2O2S:
272.0620, found 272.0622.
Tetraethyl 1,2,3,4,5,6,7,8-octahydro-2,3,6,7-anthracene-
tetracarboxylate 269b
40% yield, a white solid; mp 142-144 C; 1H NMR (300
MHz, CDCl3)
6.83 (s, 2H), 4.18 (q, J = 7.2 Hz, 8H),
H
2,8-Diphenyl-1,2,3,3a,4,6,6a,7,8,9,9a,10,12,12a-Tetradeca-
hydropyrrolo[3 ,4 :6,7]naphtho[2,3-f]isoindole-1,3,7,9-
tetraone 21
3.11-2.89 (m, 12H), 1.28 (t, J = 7.1 Hz, 12H); 13C NMR (75
MHz, CDCl3) c 174.35 (Cq), 131.95 (Cq), 128.34 (CH),
60.73 (CH2), 42.16 (CH3), 31.33 (CH2), 14.11 (CH3); MS (EI)
m/z 474 (M+, 12), 400 (30), 355 (15), 326 (37), 281 (25), 253
(29), 179 (100). HRMS calcd for C26H34O8 474.2254, found
16% yield, a white solid; mp > 270 C; H 7.16-7.09 (m,
8H), 6.83-6.80 (m, 4H), 3.41-3.39 (m, 4H), 3.20-3.14 (m,

82 J. Chin. Chem. Soc., Vol. 49, No. 1, 2002
Wu et al.
2873. (b) Oppolzer, W. Synthesis 1978, 793. (c) Mar tin, N.;
Seoane, C.; Hanak, M. Org. Prep. Proced. Int. 1991, 23,
237. (d) Segura, J. L.; Mar tin, N. Chem. Rev. 1999, 99, 3199.
2. Kametani, T. Pure Appl. Chem. 1979, 51, 747.
3. For 1,4-elimination meth ods, see (a) Ito, Y.; Nakatsuka, M.;
Saegusa, T. J. Am. Chem. Soc. 1982, 104, 7609. (b) Inaba,
S.-i.; Wehmeyer, R. M.; Forkner, M. W.; Rieke, R. D. J. Org.
Chem. 1988, 53, 339.
474.2239.
Di ethyl 2,2-dioxo-2,3,5,6,7,8-hexahydro-1H-2 6-naphtho-
[2,3-c]thiophene-6,7-dicarboxylate 27
42% yield, a white solid; mp 127-128 C; 1H NMR (300
MHz, CDCl3) H 7.06 (s, 2H), 4.30 (s, 4H), 4.17 (q, 7.2, 4H),
3.18-2.95 (m, 6H), 1.28 (t, J = 6.9 Hz, 6H); 13C NMR (75
MHz, CDCl3) c 173.84 (Cq), 135.02 (Cq), 129.20 (Cq),
125.95 (CH), 60.95 (CH2), 59.56 (CH2), 41.62 (CH), 31.17
(CH2), 14.10 (CH3); MS (EI) m/z 366 (M+, 13), 321 (19), 292
4. Flynn, C. R.; Michl, J. J. Am. Chem. Soc. 1974, 96, 3280.
5. Oppolzer, W. Heterocycles 1980, 14, 1615.
6. (a) Cava, M. P.; Shir ley, R. L. J. Am. Chem. Soc. 1960, 82,
654. (b) Gisin, M.; Wirz, J. Helv. Chim. Acta1976, 59, 2273.
7. (a) Chung, W.-S.; Lin, W.-J.; Liu, W.-D.; Chen, L.-G. J.
Chem. Soc. Chem. Commun. 1995, 2537. (b) Chung, W.-S.;
Liu, J.-H. Chem. Commun. 1997, 205. (c) Liu, J.-H.; Wu,
A.-T.; Huang, M.-H.; Wu, C.-W.; Chung, W.-S. J. Org.
Chem. 2000, 65, 3395.
(60), 228 (80), 155 (100). HRMS calcd for C H22O6S
366.1137, found 366.1137.
18
ACKNOWLEDGEMENT
8. For a re view of sultines see: Dittmer, D. C.; Hoey, M. D. The
Chem is try of Sulphinic Acids, Es ters and Their De riv a tives;
Wiley: Chichester, 1990; pp 239-273.
WethanktheNationalScienceCounciloftheRepublic
of China for fi nan cial sup port. WS wishes to thank one of the
refereesforhelpfulsuggestions.
9. ForrelatedtandemDiels-Alderreactionssee(a)Rubello, A.;
Vogel, P. Helv. Chim. Acta 1988, 71, 1268. (b) Reynolds, J.
H.; Berson, J. A.; Kumashiro, K. K.; Duchamp, J. C.; Zilm,
K. W.; Scaiano, J. C.; Berinstain, A. B.; Rubello, A. A.;
Vogel, P. J. Am. Chem. Soc. 1993, 115, 8073. (c) Lu, H. S.
M.; Berson, J. A. J. Am. Chem. Soc. 1996, 118, 265.
10. For an in ter est ing ap pli ca tion of this bis-o-QDM strat egy,
see: Gügel, A.; Belik, P.; Wal ter, M.; Kraus, A.; Harth, E.;
Wag ner, M.; Spickermann, J.; Müllen, K. Tetrahedron 1996,
52, 5007.
Received August 14, 2001.
Key Words
Naphthosultine; Benzodisultine; Pyrolysis;
Diels-Alder reaction; o-Quinodimethanes;
Tetramethylenebenzene.
11. Hebbelynck, M. F.; Mar tin, R. H. Bull. Soc. Chim. Belges.
1950, 59, 206.
REFERENCES
1. (a) Charlton, J. L.; Alauddin, M. M. Tetrahedron1987, 43,