Lewis Acid-Mediated Addition of 1,2-Naphthoquinones with 1,1-Diarylethylenes and Photocyclization of the Adducts: A Facile Synthesis of 3,12-Disubstituted Chrysene-5,6-diones

Full text of DOI:10.1021/jo961824v

2658
J . Org. Chem. 1997, 62, 2658-2661
Sch em e 1
Lew is Acid -Med ia ted Ad d ition of
1,2-Na p h th oqu in on es w ith
1,1-Dia r yleth ylen es a n d P h otocycliza tion of
th e Ad d u cts: A F a cile Syn th esis of
3,12-Disu bstitu ted Ch r ysen e-5,6-d ion es
Akio Takuwa,* Ikuo Kameoka, Akihisa Nagira,
Yutaka Nishigaichi, and Hidetoshi Iwamoto
Department of Chemistry, Faculty of Science, Shimane
University, Nishikawatsu-cho, Matsue 690, J apan
Received September 24, 1996
Polycyclic aromatic compounds have attracted much
attention because of their physicochemical and biochemi-
cal properties.1 In order to investigate the metabolism
of carcinogenic polyaromatic hydrocarbons, a facile syn-
thetic route to them is desirable. The Diels-Alder
reaction2 and photochemical cycloaddition reaction3 be-
tween 1,4-naphthoquinones and 1,1-diarylethylenes or
styrene derivatives have been very extensively developed
as one of the promised syntheses of benz[a]anthracene-
7,12-diones, which can be reduced to the corresponding
polycyclic aromatic hydrocarbons. However, Gates re-
ported that 1,2-naphthoquinone thermally added only to
the very highly polarized 1,1-bis[p-(dimethylamino)phen-
yl]ethylene to give a conjugate addition product,4 and we
also reported that 1,2-naphthoquinone photochemically
reacted as a heterodiene with 1,1-diphenylethylenes to
give dihydrodioxins.5 Thus, a synthetic method of chry-
sene-5,6-diones has not yet been developed in the reaction
of 1,2-naphthoquinones with 1,1-diarylethylenes. Here
we report that a convenient Lewis acid-promoted addition
reaction between 1,2-naphthoquinones and 1,1-diaryl-
ethylenes and subsequent photocyclization of the addition
products leads to the regioselective formation of 3,12-
disubstituted chrysene-5,6-diones in excellent to good
yields, which are the expected precursor of the corre-
sponding aromatic hydrocarbons.
Ad d ition Rea ction s of 1,1-Dia r yleth ylen es to 1,2-
Na p h th oqu in on es. The addition reaction of 1,2-naph-
thoquinone (1a ) with 1,1-diarylethylenes 2 except for the
very highly polarized 1,1-bis[p-(dimethylamino)phenyl]-
ethylene (2e)4 occurred in the absence of BF3‚OEt2. In
contrast, the addition reaction of 2a -e to 1a smoothly
proceeded in dichloromethane at -10 °C in the presence
of BF3‚OEt2 to give the ethylene adducts, 4-(2,2-dia-
rylethenyl)-1,2-naphthoquinones 6a -e, in moderate to
good yields except for the reaction between 1a and 2b
(Scheme 1, Table 1). Other functionalized quinones,
3-chloro- (1b), 3-bromo- (1c), and 3-methoxy-1,2-naph-
thoquinone (1d ), also reacted regioselectively with 1,1-
diarylethylenes in the presence of BF3‚OEt2 to afford the
corresponding ethylene adducts 6f-l, in moderate to
Ta ble 1. BF 3-P r om oted Ad d ition Rea ction of
1,2-Na p h th oqu in on es w ith 1,1-Dia r yleth ylen esa
quinone
ethylene
product
yieldb/%
1a
1a
1a
1a
1a
1b
1b
1b
1b
1b
1c
1d
2a
2b
2c
2d
2e
2a
2b
2c
2d
2e
2a
2a
6a , X ) H; R ) H
58c
6b, X ) H; R ) Cl
6c, X ) H; R ) Me
6d , X ) H; R ) OMe
6e, X ) H; R ) NMe2
6f, X ) Cl; R ) H
6c
83
95
95
96
6g, X ) Cl; R ) Cl
6h , X ) Cl; R ) Me
6i, X ) Cl; R ) OMe
6j, X ) Cl; R ) NMe2
6k , X ) Br; R ) H
6l, X ) OMe; R ) H
37 (61)d,e
97
98
98
97
39f (88)d
a
The reactions of 1 and 2 (1.3 equiv) were carried out in the
presence of BF3‚OEt2 (1.5 equiv) in a dichloromethane solution at
b
-10 °C under nitrogen atmosphere for 30 min. Isolated yields.
c When TiCl4 or Ti(OPri)Cl3 was used as a Lewis acid, the yield of
d
the product was not improved. Yields in parentheses refer to use
of Ti(OPri)Cl3 as a Lewis acid. e When TiCl4 and Ti(OPri)4 were
used as Lewis acid, 6g was obtained in 18 and 3% yields,
respectively. f Two unidentified products were also formed.
almost quantitative yields. Thus, the yields of 6 de-
pended upon the nature of the substituents of both 1 and
2. Among Lewis acids examined here, BF3‚OEt2 was the
one of the best acids for the addition reaction listed in
Table 1, but in the reactions of 1b with 2b and of 1d
with 2a , Ti(OPri)Cl3 was superior to other Lewis acids
such as BF3‚OEt2, TiCl4, or Ti(OPri)4. However, the
yields of 6a and 6b were not improved by using TiCl4 or
Ti(OPri)Cl3 in the reactions of 1a with 2a or 2b because
1,2-naphthoquinone 1a decomposed in the presence of
these Lewis acids under the present conditions.
(1) (a) Harvey, R. G. Acc. Chem. Res. 1981, 14, 218. (b) Lowe, J . P.;
Silverman, B. D. J . Am. Chem. Soc. 1981, 103, 2582. (c) Tsang, W. S.;
Griffin, G. W.; Horning, M. G.; Stillwell, W. G. J . Org. Chem. 1982,
47, 5339. (d) Boyd, D. R.; Stubbs, M. E. J . Am. Chem. Soc. 1983, 105,
2554.
(2) (a) Manning, W. B.; Muschik, G. M.; Tomaszewski, J . E. J . Org.
Chem. 1979, 44, 699. (b) Muschik, G. M.; Tomaszewski, J . E.; Sato,
R. I.; Manning, W. B. Ibid. 1979, 44, 2150.
(3) (a) Maruyama, K.; Otsuki, T.; Mitsui, K. Bull. Chem. Soc. J pn.
1976, 49, 3361. (b) Maruyama, K.; Otsuki, T.; Mitsui, K. J . Org. Chem.
1980, 45, 1424. (c) Maruyama, K.; Otsuki, T.; Tai, S. J . Org. Chem.
1985, 50, 52.
(4) (a) Gates, M. J . Am. Chem. Soc. 1944, 66, 124. (b) Gates, M. J .
Org. Chem. 1982, 47, 578.
The formation of ethylene adducts 6 can be rationalized
as follows. Coordination of a Lewis acid to quinone
carbonyl enhances the electrophilic character of the C-4
carbon in 16 and facilities the nucleophilic attack of 2 on
(6) (a) Takuwa, A.; Naruta, Y.; Soga, O.; Maruyama, K. J . Org.
Chem. 1984, 49, 1857. (b) Takuwa, A.; Soga, O.; Iwamoto, H.;
Maruyama, K. Bull. Chem. Soc. J pn. 1986, 59, 2959. (c) Takuwa, A.;
Soga, O.; Mishima, T.; Maruyama, K. J . Org. Chem. 1987, 52, 1261.
(5) Takuwa, A. Chem. Lett. 1989, 5.
S0022-3263(96)01824-5 CCC: $14.00 © 1997 American Chemical Society

Notes
J . Org. Chem., Vol. 62, No. 8, 1997 2659
Ta ble 2. P h otocycliza tion of Eth ylen e Ad d u cts 6a
Sch em e 2
irradiatn time/h (product yield/%)b
ethylene adduct product
0.5
2
4
12
6f
6g
6h
6i
6j
6j
9a
9b
9c
9d
9e
9e
(38)
(22)
(40)
(10)
(0)
(97)
(86)
(80)
(38)
(0)
(97)
(96)
(62)
(0)
(95)
(0)
(97)c
a
Irradiation was carried out in an acetonitrile solution (10 mL)
of 6 (0.1 mmol). b Yields were determined by 1H-NMR. c Irradiation
was carried out in the presence of trifluoroacetic acid.
6a (X ) H) or followed by trans â-elimination of HX for
6f (X ) Cl), 6k (X ) Br), and 6l (X ) OMe) to be stabilized
by aromatization (Scheme 2). The rather air-sensitive
1,2-diol intermediate 7 produced in the photocyclization
processes of 6a was trapped as diacetyl derivative 8 upon
treatment of the irradiated mixture of 6a with acetic
anhydride-pyridine.
From an organic synthetic point of view, we examined
the photochemical cyclizations of ethylene adducts 6f-j
because they were obtained in good to almost quantita-
tive yields from the Lewis acid-promoted addition reac-
tion of 3-chloro-1,2-naphthoquinone 1b with 2a -e as
shown in Table 1. The results are summarized in Table
2. All of the ethylene adducts except for 6i and 6j
produced the corresponding polycyclic aromatic quinones
9a -c in very high yields (>95%) upon irradiation for 2-4
h. A longer irradiation (12 h) was required for complete
transformation of 6i to 9d . Thus, the photocyclization
reaction tends to be depressed by the electron-donating
substituent in the 1,1-diphenylethenyl moiety of the
ethylene adducts.
In contrast to these ethylene adducts, no cyclization
reaction occurred in the irradiation of 3-chloro-4-[2,2-bis-
(p-dimethylamino)phenyl]-1,2-naphthoquinone (6j). How-
ever, when irradiation of 6j was carried out in the
presence of trifluoroacetic acid, the corresponding chry-
sene-5,6-dione 9e was obtained in a very high yield as
shown in Table 2. In the presence of a large excess (100
equiv) of trifluoroacetic acid, a broad electronic absorption
maximum of 6j probably due to intramolecular charge-
transfer band shifted from 610 (ꢀmax 9250) to 425 nm (ꢀmax
600) in acetonitrile, where the protonation probably
occurred on the nitrogen atom of the electron-releasing
dimethylamino group.8 As a result of loss of the strongly
electron-donating ability of the dimethylamino group by
the protonation, the photocyclization of 6j came to
proceed to give 9e. Thus, the desired 3,12-disubstituted
chrysene-5,6-diones 9a -e could be obtained in very high
yields by photochemical intramolecular cyclization of the
ethylene adducts 6f-j.
that carbon. The resulting 2,5-cyclohexadienone inter-
mediate may be deprotonated and enolize to afford the
rather air-sensitive primary adduct, 4-substituted 1,2-
naphthalenediols 3, which are oxidized into the corre-
sponding 1,2-quinones 6 during workup or isolating
procedures. The diols 3 could be trapped as the diac-
etates 4 or 5 by treatment of the reaction mixture
between 1a or 1b and 2a with acetic anhydride-pyridine
under nitrogen atmosphere (Scheme 1).
As can be seen in the BF3‚OEt2-mediated reactions
(Table 1), the order of reactivities of para-disubstituted
1,1-diphenylethylenes 2a -e toward 1a increased in the
order of electron-donating character of the substituent
(2e > 2d > 2c > 2a > 2b). On the other hand, the nature
of the substituent on quinones 1 could exert opposite
influences on the yields of the ethylene adducts 6. An
electron-withdrawing substituent such as chloro or bromo
enhances the electrophilic character of the C-4 carbon of
1b or 1c to give 6f or 6k in a very high yield, respectively,
while the methoxy group diminishes the electrophilicity
of that carbon to afford 6l in a low yield.
P h otocycliza tion of Eth ylen e Ad d u cts to Ch r y-
sen e-5,6-d ion es. When the ethylene adduct 6a in an
NMR sample tube (CDCl3) was allowed to stand for 6 h
in a laboratory, it was transformed partially into 12-
phenylchrysene-5,6-dione (9a ), but under dark conditions
1
the cyclization product 9a could not be detected by H-
NMR analysis. This clearly indicated that 6a gradually
cyclizes to 9a even under a room light. This evidence
prompted us to investigate the photocyclization reaction
of 6, which has the promising potential of a new conve-
nient method for the synthesis of regioselectivity substi-
tuted chrysene-5,6-diones 9 (Scheme 2).
The ethylene adducts 6a , f, k , l were irradiated
independently in CH3CN with a light (>300 nm) from a
300-W high-pressure Hg arc lamp for 2 h to give the same
photocyclized product 9a in 93, 95, 90, and 6% yields,
respectively. The chrysene-5,6-dione (9a) could be formed
via photochemical [π2s + π4a] cyclization7 followed by
enolization and air oxidation of the resulting diol 7 for
The chrysene-5,6-diones 9a and 9c were reduced by
lithium aluminum hydride to the corresponding aromatic
hydrocarbons such as 10 and 11. Likewise, they were
converted to the diacetoxy derivatives 8 and 12 by
reductive acetylation with zinc-acetic anhydride.
Exp er im en ta l Section
All 1,2-naphthoquinones 1a ,9 1b,10 1c,11 and 1d 12 were
prepared by the methods described in the literature. 1,1-
Diarylethylenes were commercially available and/or synthesized
(9) Fieser, L. F. Organic Syntheses; Wiley: New York, 1943; Collect.
Vol. II, p 430.
(7) Floyd, A. J .; Dyke, S. F.; Ward, S. E. Chem. Rev. 1976, 76, 509.
(8) Yokoyama, Y.; Yamane, T.; Kurita, Y. J . Chem. Soc., Chem.
Commun. 1991, 1722.
(10) Zincke, T. Chem. Ber. 1886, 19, 2497.
(11) Zincke, T. Chem. Ber. 1886, 19, 2495.
(12) Teuber, H-J .; Gotz, N. Chem. Ber. 1954, 87, 1236.

2660 J . Org. Chem., Vol. 62, No. 8, 1997
Notes
cm-1; δH δ 2.24 (3H, s), 2.41 (3H, s), 6.68 (1H, s), 7.00 (4H, q, J
) 8.1 Hz), 7.21 (2H, d, J ) 7.8 Hz), 7.34 (2H, d, J ) 7.8 Hz),
7.38-7.56 (3H, m), 8.03 (1H, dd, J ) 7.5, 1.7 Hz); MS m/ z 398
(M+).
3-Ch lor o-4-[2,2-bis(p-m eth oxyp h en yl)eth en yl]-1,2-n a p h -
th oqu in on e (6i): red crystals (from benzene-hexane); mp
145-146 °C; νmax 1695, 1670 cm-1; δH 3.73 (3H, s), 3.87 (3H, s),
6.63 (1H, s), 6.69 (2H, d, J ) 8.8 Hz), 6.93 (2H, d, J ) 8.8 Hz),
7.07 (2H, d, J ) 8.8 Hz), 7.34-7.53 (5H, m), 8.03 (1H, dd, J )
7.3, 1.7 Hz); δC 55.2, 55.5, 113.7 (×2), 113.9 (×2), 118.5, 128.4
(×2), 129.2, 130.1 (×2), 130.2, 130.3, 131.1 (×2), 131.9, 133.8,
134.1, 135.3, 150.4, 150.5, 160.2, 160.6, 174.5, 178.2; MS m/ z
430 (M+).
3-Ch lor o-4-[2,2-bis[p-(d im eth yla m in o)p h en yl]eth en yl]-
1,2-n a p h th oqu in on e (6j): violet blue crystals (from benzene-
hexane); mp 238-242 °C; νmax 1696, 1661, 1604, 1523, 1361,
1192, 824 cm-1; δH 2.89 (6H, s), 3.03 (6H, s), 6.43 (2H, d, J )
8.8 Hz), 6.57 (1H, s), 6.71 (2H, d, J ) 9.0 Hz), 7.01 (2H, d, J )
9.0 Hz), 7.23-7.47 (5H, m), 7.95-7.98 (1H, m); MS m/ z 456
(M+).
3-Br om o-4-(2,2-d ip h en ylet h en yl)-1,2-n a p h t h oq u in on e
(6k ): red needles (from benzene-hexane); mp 195-198 °C; νmax
1670 cm-1; δH 6.72 (1H, s), 7.14-7.57 (13H, m), 8.14 (1H, dd, J
) 6.8, 1.4 Hz); MS m/ z 414 (M+), 416 (M+).
4-(2,2-D i p h e n y le t h e n y l)-3-m e t h o x y -1,2-n a p h t h o -
qu in on e (6l): dark red prisms (from hexane-benzene); mp
130-132 °C; νmax 1696, 1662, 1562, 1334, 1188 cm-1; δH 3.55
(3H, s), 6.64 (1H, s), 7.16-7.50 (13H, m), 7.97 (1H, dd, J ) 8.1,
1.5 Hz); MS m/ z 366 (M+).
Tr a p p in g of th e Eth ylen e Ad d u cts a s Acetyl Der iva -
tives. The addition reaction of 1a (39.5 mg, 0.25 mmol) with
2a (68 mg, 0.37 mmol) in the presence of BF3‚OEt2 was
undertaken according to the general procedure described above.
The treatment of the reaction mixture with acetic anhydride-
pyridine gave 1,2-diacetoxy-4-(2,2-diphenylethenyl)naphthalene
4 (63 mg) as prisms (from methanol): mp 173-175 °C; δH 2.18
(3H, s), 2.42 (3H, s), 6.85 (1H, s), 7.07-7.56 (13H, m), 7.82 (1H,
dd, J ) 7.6, 1.7 Hz), 8.15 (1H, dd, J ) 6.6, 1.9 Hz); νmax 1770,
1371, 1208, 1154, 767 cm-1; MS m/ z 442 (M+), 380 [M -
(CH2dCdO)], 338 [M - 2(CH2dCdO)].
Similar treatment of the reaction mixture of 1b (48 mg) and
2a with acetic anhydride-pyridine afforded 3-chloro-1,2-diac-
etoxy-4-(2,2-diphenylethenyl)naphthalene (5) (89 mg) as prisms
(from methanol-benzene): mp 221-223 °C; δH 2.34 (3H, s), 2.42
(3H, s), 6.97-7.05 (6H, m), 7.34-7.50 (7H, m), 7.70 (1H, d, J )
7.1 Hz), 7.99 (1H, d, J ) 7.8 Hz); δC 20.3, 20.4, 121.4, 122.3,
126.0, 126.1, 126.2, 126.9 (×2), 127.6, 127.8 (×2), 128.2, 128.3
(×2), 128.4 (×2), 129.6 (×2), 130.3, 133.7, 136.4, 137.9, 139.3,
142.3, 148.1, 167.5, 167.9; νmax 1773, 1369, 1198, 1151, 766, 700
cm-1; MS m/ z 456 (M+), 414 [M - (CH2dCdO)], 372 [M -
2(CH2dCdO)].
Gen er a l P r oced u r e for P h otoch em ica l Cycliza tion Re-
a ction of th e Eth ylen e Ad d u cts 6. An acetonitrile solution
(10 mL) of an ethylene adduct 6 (0.1 mmol) was irradiated at
room temperature under N2 by a high-pressure Hg arc lamp (300
W). The amount of the ethylene adduct consumed was followed
by TLC. After the complete consumption of the ethylene adduct,
the reaction mixture was concentrated in vacuo to give crude 9,
which was further purified by recrystallization or preparative
TLC on silica gel. In the case of the photochemical cyclization
reaction of 6j, irradiation was carried out in the presence of a
large excess (100 equiv) of trifluoroacetic acid.
by using the method of Allen et al.13 Dichloromethane and
acetonitrile were distilled from calcium hydride. The Lewis acids
were commercially available and used without further purifica-
tions. The 1H-NMR and 13C-NMR spectra were run in chloro-
form-d and measured on a 270 MHz instrument. Satisfactory
analytical data ((0.4% for C, H, N) were obtained for all new
compounds.
Gen er a l P r oced u r e for th e Ad d ition Rea ction . To a
dichloromethane solution (20 mL) of 1 (0.5 mmol) was added a
Lewis acid (1.5 mmol) under N2 at -10 °C. After a few minutes,
2 (0.6 mmol) was added dropwise, and the reaction mixture was
stirred for 0.5 h at that temperature. The reaction mixture was
quenched with a saturated aqueous ammonium chloride solution
and then extracted with ether. The combined organic extracts
were washed with water followed by brine and dried over
anhydrous sodium sulfate. Evaporation of the solvent gave the
residue, which was purified by column chromatography over
silica gel (eluent: hexane-ether mixture) to yield the crude
ethylene adducts 6, which were further purified by TLC or
recrystallization and identified by their physical and spectral
characteristics.
P h ysica l P r op er ties of th e Eth ylen e Ad d u cts. 4-(2,2-
Dip h en ylet h en yl)-1,2-n a p h t h oq u in on e (6a ): orange red
crystals (from benzene-hexane); mp 193-195 °C; νmax 1695,
1655 cm-1; δH 6.06 (1H, d, J ) 1.2 Hz), 6.91 (1H, d, J ) 1.2 Hz),
7.14-7.70 (8H, m), 7.39 (5H, s), 8.14 (1H, dd, J ) 7.5, 1.2 Hz);
δC 122.6, 127.4, 128.0, 128.4 (×2), 128.6 (×2), 128.7 (×2), 128.8
(×2), 129.1, 129.7 (×2), 130.1, 130.8,, 131.5, 135.4, 135.6, 138.7,
141.8, 151.0, 152.7, 179.2, 180.4; MS m/ z 336 (M+).
4-[2,2-Bis(p -ch lor op h en yl)et h en yl]-1,2-n a p h t h oq u in o-
n e (6b): orange red crystals (from benzene-hexane); mp 182-
184 °C; νmax 1695, 1660 cm-1; δH 6.06 (1H, d, J ) 1.2 Hz), 6.89
(1H, d, J ) 1.2 Hz), 7.07-7.67 (11H, m), 8.16 (1H, dd, J ) 7.5,
1.2 Hz); MS m/ z 404 (M+).
4-(2,2-Di-p-tolyleth en yl)-1,2-n a p h th oqu in on e (6c): red
crystals (from benzene-hexane); mp 173-174 °C; νmax 1685,
1650 cm-1; δH 2.32 (3H, s), 2.41 (3H, s), 6.06 (1H, s), 6.84 (1H,
s), 7.05-7.71 (11H, m), 8.12 (1H, d, J ) 7.6 Hz); MS m/ z 364
(M+).
4-[2,2-Bis(p-m eth oxyp h en yl)eth en yl]-1,2-n a p h th oqu in o-
n e (6d ): red oil; νmax 1695, 1660 cm-1; δH 3.79 (3H, s), 3.86 (3H,
s), 6.09 (1H, d, J ) 1.2 Hz), 6.76 (1H, d, J ) 1.2 Hz), 6.79 (2H,
d, J ) 8.8 Hz), 6.91 (2H, d, J ) 8.8 Hz), 7.09 (2H, d, J ) 8.8 Hz),
7.32 (2H, d, J ) 8.8 Hz), 7.49-7.73 (3H, m), 8.14 (1H, dd, J )
7.6, 1.5 Hz); MS m/ z 396 (M+).
4-[2,2-Bis[p-(d im eth yla m in o)p h en yl]eth en yl]-1,2-n a p h -
th oqu in on e (6e): physical and spectroscopic properties agreed
with the data reported in ref 4.
3-Ch lor o-4-(2,2-d ip h en ylet h en yl)-1,2-n a p h t h oq u in on e
(6f): orange red crystals (from benzene); mp 181-182 °C; νmax
1665 cm-1; δH 6.76 (1H, s), 7.12-7.57 (13H, m), 8.14 (1H, dd, J
) 7.3, 1.2 Hz); δC 120.6, 128.3 (×2), 128.6 (×4), 129.0, 129.1,
129.2, 129.4 (×2), 130.1, 130.4, 130.5, 131.0, 133.9, 135.5, 139.1,
141.0, 149.9, 150.6, 174.3, 177.8.
3-Ch lor o-4-[2,2-b is(p -ch lor op h en yl)et h en yl]-1,2-n a p h -
th oqu in on e (6g): orange red crystals (from benzene-hexane);
mp 205-208 °C; νmax 1690, 1670 cm-1; δH 6.73 (1H, s), 7.05-
7.53 (11H, m), 8.09 (1H, d, J ) 7.1 Hz); MS m/ z 438 (M+), 440
(M + 2), 442 (M + 4).
P h ysica l P r op er ties of th e Cycliza tion P r od u cts. 12-
P h en ylch r ysen e-5,6-d ion e (9a ): orange red needles (from
benzene-hexane); mp 245-247 °C; δH 7.46-7.74 (9H, m), 7.86
(1H, d, J ) 7.8 Hz), 8.03 (1H, s), 8.10 (1H, d, J ) 7.8 Hz), 8.17
(1H, dd, J ) 7.8, 1.5 Hz), 9.50 (1H, d, J ) 8.8 Hz); νmax 3070,
3050, 1685, 1665, 1590, 1480, 1410, 1300, 760 cm-1; MS m/ z
334 (M+).
3-Ch lor o-12-(p-ch lor oph en yl)ch r ysen e-5,6-dion e (9b): red
crystals; mp 268-270 °C; δH 7.41-7.79 (8H, m), 7.99 (1H, s),
8.08 (1H, d, J ) 7.6 Hz), 8.17 (1H, dd, J ) 7.6, 1.5 Hz), 9.56
(1H, d, J ) 2.2 Hz); MS m/ z 402 (M+), 404 (M + 2), 406 (M +
4).
3-Ch lor o-4-(2,2-p -d it olylet h en yl)-1,2-n a p h t h oq u in on e
(6h ): orange crystals (from benzene); mp 164-166 °C; νmax 1670
3-Meth yl-12-p-tolylch r ysen e-5,6-d ion e (9c): red needles
(benzene); mp 195-197 °C; δH 2.50 (3H, s), 2.57 (3H, s), 7.30-
7.50 (6H, m), 7.69 (1H, dt, J ) 7.6, 1.5 Hz), 7.78 (1H, d, J ) 8.8
Hz), 7.93 (1H, s), 8.07 (1H, d, J ) 7.6 Hz), 8.15 (1H, dd, J ) 7.6,
(13) Allen, C. F. H.; Converse, S. Organic Syntheses; Wiley: New
York, 1941; Collect. Vol. I, p 226.

Notes
J . Org. Chem., Vol. 62, No. 8, 1997 2661
1.5 Hz), 9.31 (1H, s); νmax 1690, 1670, 1590, 1360, 1300, 830,
765 cm-1; MS m/ z 362 (M+).
3-Meth yl-12-p-tolylch r ysen e (11): white crystals; mp 45-
49 °C; yield 23%; δH 2.51 (3H, s), 2.68 (3H, s), 7.34 (2H, d, J )
8.1 Hz), 7.33-7.43 (1H, m), 7.53 (2H, d, J ) 8.1 Hz), 7.57-7.71
(2H, m), 7.93 (1H, d, J ) 8.5 Hz), 8.01 (2H, d, J ) 8.5 Hz), 8.57
(1H, s), 8.65 (1H, s), 8.77 (2H, d, J ) 8.9 Hz); δC 29.4, 29.7, 121.2,
121.3, 123, 123.2, 126.6, 126.9, 127.0, 127.4, 128.2 (d), 128.5,
128.8, 129.0, 129.1, 129.2, 130.1 (×2), 130.6, 131.1, 132.2, 136.2,
3-Me t h oxy-12-(p -m e t h oxyp h e n yl)ch r yse n e -5,6-d ion e
(9d ): red prisms (benzene-hexane); mp 253-255 °C; δH 3.91
(3H, s), 4.03 (3H, s), 7.08-7.51 (6H, m), 7.71 (1H, dt, J ) 8.1,
1.5 Hz), 7.81 (1H, d, J ) 9.3 Hz), 7.89 (1H, s), 8.11 (1H, d, J )
8.1 Hz), 8.18 (1H, dd, J ) 8.1, 1.5 Hz), 9.14 (1H, dd, J ) 8.1, 2.7
Hz); νmax 1686, 1649, 1610, 1581, 1244, 1217 cm-1; MS m/ z 394
(M+).
3-(Dim eth yla m in o)-12-[p-(d im eth yla m in o)p h en yl]ch r y-
sen e-5,6-d ion e (9e): dark blue needles; mp >300 °C; δH 3.10
(6H, s), 3.20 (6H, s), 6.88 (2H, d, J ) 9.0 Hz), 7.06 (1H, dd, J )
9.3, 2.4 Hz), 7.43 (1H, t, J ) 7.8 Hz), 7.45 (2H, d, J ) 9.0 Hz),
7.66 (1H, dt, J ) 7.8, 1.5 Hz), 7.72 (1H, s), 7.87 (1H, d, J ) 9.3
Hz), 8.09 (1H, d, J ) 7.8 Hz), 8.16 (1H, dd, J ) 7.8, 1.5 Hz),
8.99 (1H, d, J ) 2.4 Hz); νmax 1680, 1640, 1608, 1562, 1360, 1334,
1188, 818 cm-1; MS m/ z 420 (M+).
Tr a p p in g of 12-P h en ylch r ysen e-5,6-d iol (7) a s Acet yl
Der iva tives. After irradiation of 6a in acetonitrile under N2,
acetic anhydride and pyridine were added to the irradiated
mixture. Usual workup afforded 5,6-diacetoxy-12-phenylchry-
sene (8) in 70% yield, whose physical properties were described
below.
Red u ction of Ch r ysen e-5,6-d ion es to th e Cor r esp on d in g
Ar om a tic Hyd r oca r bon s. A tetrahydrofuran solution (20 mL)
of 9a or 9c (0.1 mmol) and an excess amount (ca. 10 equiv) of
lithium aluminum hydride was refluxed for 12 h. After hydroly-
sis, the reaction mixture was chromatographed on silica gel to
give the corresponding aromatic hydrocarbon.
137.1, 138.5, 139.2; νmax 2919, 1620, 1506, 1435 824, 763 cm-1
MS m/ z 332 (M+).
;
Red u ctive Acetyla tion of Ch r ysen e-5,6-d ion es. Chry-
sene-5,6-dione 9a and 9c (0.2 mmol) and an excess amount of
zinc powder were added to acetic anhydride (2 mL). After the
reaction mixture was refluxed for 30 min, the reaction mixture
was hydrolyzed and neutralized with an aqueous solution of
sodium carbonate. The corresponding diacetate 8 or 12 was
extracted with ether and purified by recrystallization.
P h ysica l P r op er ties of Dia ceta tes. 5,6-Dia cetoxy-12-
p h en ylch r ysen e (8): needles (from ethanol-benzene); yield
84%; mp 251-252 °C; δH 2.55 (3H, s), 2.57 (3H, s), 7.50-7.73
(9H, m), 7.93-8.01 (2H, m), 8.63 (1H, s), 8.76-8.80 (1H, m), 9.25
(1H, d, J ) 9.2 Hz); νmax 1773, 1368, 1201, 1098, 760 cm-1; MS
m/ z 420 (M+), 378 [M - (CH2dCdO)], 336 [M - 2(CH2dCdO)].
5,6-Dia cetoxy-3-m eth yl-12-p-tolylch r ysen e (12): pale yel-
low needles (from ethanol-benzene); yield 70%; mp 235-237
°C; δH 2.50 (3H, s), 2.54 (3H, s), 2.56 (3H, s), 2.60 (3H, s), 7.35
(2H, d, J ) 8.0 Hz), 7.36-7.40 (1H, m), 7.48 (2H, d, J ) 8.0 Hz),
7.64-7.71 (2H, m), 7.89-7.95 (2H, m), 8.55 (1H, s), 8.74-8.77
P h ysical P r oper ties of Ar om atic Hydr ocar bon s. 6-P h en -
ylch r ysen e (10): pale yellow crystals; mp 102-105 °C; yield
27%; δH 7.47-7.75 (9H, m), 7.99-8.05 (3H, m), 8.65 (1H, s), 8.75
(1H, d, J ) 8.9 Hz), 8.77 (1H, d, J ) 8.7 Hz), 8.88 (1H, d, J )
8.9 Hz); νmax 1590, 1440, 1240, 820, 778, 762, 703 cm-1; MS m/ z
304 (M+).
(1H, m), 9.04 (1H, s); νmax 1778, 1367, 1198, 1182, 828, 763 cm-1
;
MS m/ z 448 (M+), 406 [M
2(CH2dCdO)].
- (CH2dCdO)], 364 [M -
J O961824V