Intramolecular Photochemical Reactions of Bichromophoric 3-(Alkenyloxy)phenols and 1-(Alkenyloxy)-3-(alkyloxy)benzene Derivatives. Acid-Catalyzed Transformations of the Primary Cycloadducts

Article abstract of DOI:10.1021/jo970554t

Irradiation of 3-(alkenyloxy)phenols and 1-(alkenyloxy)-3-(alkyloxy)benzene derivatives, at λ = 254 nm in acidic media, yields benzocyclobutenes, 3-alkylphenols, 3-alkylanisols, and 4-alkyl-1,2dialkyloxybenzenes depending on the substitution pattern of the aromatic ring and the olefinic side chain. The final products are derived from an intramolecular [2 + 2] photocycloaddition and acidic rearrangements from a common intermediate.

Full text of DOI:10.1021/jo970554t

6952
J . Org. Chem. 1997, 62, 6952-6960
In tr a m olecu la r P h otoch em ica l Rea ction s of Bich r om op h or ic
3-(Alk en yloxy)p h en ols a n d 1-(Alk en yloxy)-3-(a lk yloxy)ben zen e
Der iva tives. Acid -Ca ta lyzed Tr a n sfor m a tion s of th e P r im a r y
Cycloa d d u cts
Norbert Hoffmann and J ean-Pierre Pete*
Unite´ Mixte de Recherche CNRS, Universite´ de Reims Champagne-Ardenne, UFR Sciences,
F-51687 REIMS, Cedex 2, France
Received March 25, 1997X
Irradiation of 3-(alkenyloxy)phenols and 1-(alkenyloxy)-3-(alkyloxy)benzene derivatives, at λ ) 254
nm in acidic media, yields benzocyclobutenes, 3-alkylphenols, 3-alkylanisols, and 4-alkyl-1,2-
dialkyloxybenzenes depending on the substitution pattern of the aromatic ring and the olefinic
side chain. The final products are derived from an intramolecular [2 + 2] photocycloaddition and
acidic rearrangements from a common intermediate.
In tr od u ction
process, can have considerable interest for organic syn-
thesis of polycyclic skeletons (e.g., triquinanes).1,6 In-
tramolecular [2 + 2] photocycloaddition of (alkenyloxy)-
benzenes have been reported to give unstable intermedi-
ates in thermal or photochemical equilibrium.3,7 Until
recently, little attention had been paid to the photochem-
istry of (alkenyloxy)phenols, and only a few examples of
intermolecular [2 + 2] cycloaddition of alkenes to phenols
have been reported in the literature.8 Additionally, one
example of an intramolecular [2 + 2] photocycloaddition,9
a photocyclization of allylphenols, and a di-π-methane
photorearrangement were also described.10
Three types of cycloaddition reactions are usually
observed between photochemically excited benzene de-
rivatives and alkenes.1-3 Depending on the relative
redox potentials and on the substitution pattern of the
two reaction partners, [2 + 2], [2 + 3], or [2 + 4]
cycloadditions can be observed.4,5 In case of alkoxy-
substituted benzene derivatives, [2 + 2] addition and [2
+ 3] cycloaddition (meta-cycloaddition), the most frequent
X Abstract published in Advance ACS Abstracts, September 1, 1997.
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Synthesis, Vol. 5; Trost, B. M., Fleming, I., Paquette, L. A., Eds.;
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S., Eds.; CRC Press: Boca Raton, 1995; pp 280-290.
Photolysis of various O-alkenylsalicylic esters in neu-
tral medium was found to give complicated mixtures.
However, when the reaction was carried out in the
presence of acid, the reaction mixture was simplified and
the only isolated product could be explained through a
series of thermal and photochemical equilibria, starting
from a [2 + 2] cycloaddition. These equilibria could be
shifted efficiently to a mixed acetal by an irreversible
protonation of an enol ether intermediate.11
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Tetrahedron, 1991, 47, 3059-3074. For theoretical treatments, see:
(f) Houk, K. N. Pure Appl. Chem. 1982, 54, 1633-1650. (g) van der
Hart, J . A.; Mulder, J . J . C.; Cornelisse, J . J . Mol. Struct. (Theochem)
1987, 151, 1-10. (h) van der Hart, J . A.; Mulder, J . J . C.; Cornelisse,
J . J . Photochem. Photobiol. A: Chem. 1991, 61, 3-13. (i) Stehouwer,
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1 1992, 1145-1148. (f) Wagner, P. J .; Sakamoto, M.; Madkour, A. E.
J . Am. Chem. Soc. 1992, 114, 7298-7299. (g) Wagner, P. J .; Cheng,
K. L. Tetrahedron Lett. 1993, 34, 907-910. (h) Cheng, K. L.; Wagner,
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6802. For similar reactions of naphthalene derivatives, see: (m)
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S0022-3263(97)00554-9 CCC: $14.00 © 1997 American Chemical Society

Bichromophoric Alkenyloxy Phenols and Benzenes
J . Org. Chem., Vol. 62, No. 20, 1997 6953
Sch em e 1. P h otoch em ica l Rea ction of
3-(Alk en yloxy)p h en ols a n d
(Alk en yloxy)(a lk yloxy)ben zen e Der iva tives
In order to generalize this reaction, and to gain more
insight into the effect of acids on the photocycloaddition
of alkenes on phenol derivatives, we decided to investi-
gate O-(alkenyloxy)phenols. Surprisingly, benzocyclo-
butene derivatives were obtained in preparative yield.12
We have now compared the photoreactivity of (alkenyl-
oxy)phenols, (alkenyloxy)(alkyloxy)benzene, and (alkenyl-
oxy)bis(alkyloxy)benzene derivatives in acidic conditions.
We also describe our investigation on the effect of
substitution at the extremity of the ethylenic double bond
on the course of the reaction.
Resu lts a n d Discu ssion
When phenol 1a , having an O-butenyl chain in the
meta position, was irradiated at λ ) 254 nm, in methanol
or ethanol, only very slow transformation and complex
mixtures were observed. In contrast, when irradiation
was carried out in the presence of H2SO4, a faster reaction
and a cleaner transformation to isomeric benzocy-
clobutenes 2a and 3a was obtained (Scheme 1, Table 1).
Similarly, when phenols 1b and 1c having an O-pentenyl
and O-(3-methylbut-3-enyl) chain, respectively, were
irradiated under the same conditions, a mixture of
benzocyclobutenes 2 and 3 could be isolated as the only
new products (runs 1-3). When an alkyl substituent was
introduced at the extremity of the ethylenic bond as in
1d and 1e, the chemical yield of the corresponding
benzocyclobutenes dropped considerably, and only re-
gioisomers 3d and 3e could be characterized. Further-
more, 6, 7, and 8, which possess a rearranged skeleton,
are the main products isolated from the reaction mixture
(runs 4 and 5). These new products result from C-C
bond formation between C-3 of the phenol ring and the
C-3′ of the original alkenyloxy side chain. They can be
explained by an acidic transformation of unstable inter-
mediates. In order to determine if the presence of a
hydroxyl group on the benzene ring was needed in these
photoreactions, methoxy and 3-(alkenyloxy)benzenes 1f,
1g, and 1h were then irradiated. As for the correspond-
ing 3-(alkenyloxy)phenols, 1f and 1g gave mainly ben-
zocyclobutenes 2 and 3. However, the transformation
had become more regioselective, and 2 was sometimes
formed almost exclusively. For (alkenyloxy)(alkyloxy)-
benzene 1h having a terminally substituted alkenyl
chain, no benzocyclobutene could be isolated and the
reaction mixture containing 6h , 7h , and 8h was very
similar to the one obtained from the corresponding phenol
1d .
In very acidic medium, rearranged products 3 and 6-8
might be in equilibrium. To verify if the reaction was
under kinetic or thermodynamic control, we irradiated
3a , 6a , 7a , and 8a separately and under the same
reaction conditions. We observed a slow degradation of
the starting material and a complex mixture of products,
which did not contain the expected ones. This observa-
tion indicates that 5-8 are primary products derived
from unstable and nonisolable intermediates. To explain
the reaction products, several mechanisms could be
envisaged. A first possibility was to consider an initial
C-protonation leading to a mixture of photoreactive
cyclohexadienones according to Scheme 2. Protonation
of the aromatic ring might occur either in the ground
state before excitation or in the excited state to produce
a photoreactive cyclohexadienone-like intermediate. Then
absorption of a photon by this intermediate could lead
to an intramolecular [2 + 2] photocycloaddition. The
observed products would result from an acid-catalyzed
transformation of primary cycloadducts in the ground
state. Formation of cyclohexadienone-like intermediates
might also allow an exchange of the alkoxy groups of the
benzene ring simply by modification of the solvent of the
reaction. In order to find out if such a C-protonation of
the aromatic ring is required in the photoreaction process,
we studied the photoreactivity of anisol derivative 1f,
under different solvent conditions. In a mixture of
methanol and water, no exchange of the methoxy by a
hydroxy group could be detected, either in the recovered
starting material or in rearranged products 2, 3, and 4.
Similarly, when the reaction was carried out in acidic
ethanol, there was no exchange of the methoxy by an
ethoxy group on the aromatic ring (runs 7 and 8) but an
incorporation of an ethoxy group on the side chain of 4.
Furthermore, when CH3OH was replaced by CH3OD
while the other conditions remained the same, no sig-
nificant deuterium incorporation could be detected either
in the reactant 1f or in the products 2f, 3f, and 4f
(12) Hoffmann, N.; Pete, J . P. Tetrahedron Lett. 1996, 37, 2027-
2030.

6954 J . Org. Chem., Vol. 62, No. 20, 1997
Hoffmann and Pete
Ta ble 1. Resu lts of th e P h otoch em ica l Rea ction of 3-(Alk en yloxy)p h en ols a n d (Alk en yloxy)(a lk yloxy)ben zen e
Der iva tives
yield, %a
conversion,
a
run
1
X
OR
n
R1
R2
solvent
MeOH
MeOH
MeOH
MeOH
MeOH
MeOH
EtOH
%
2
3b
4
5
6
7
8
9
1
2
3
4
5
6
7
8
a
b
c
d
e
f
H
H
H
H
H
H
OH
OH
OH
OH
OH
OMe
1
2
1
1
1
1
H
H
H
Me
Et
H
H
H
Me
H
H
83
45
39
50
5
20
10
13
11
2
77
50
73
86
86
84
94
10
20
10
37
15
i
i
40c
H
41
31
28
20d
18e
MeOH-
H2O (5/1)
17/4f
9
10
11
12
13
14
15
16
g
H
H
OMe
OMe
OCH2O
OCH2O
2
H
H
MeOH
MeCN
MeOH
MeOH
MeOH
MeCN
MeOH
MeOH
100
82
>97
100
54
70
100
93
33
20
8
6
23
4
25
h
i
j
1
1
2
Me
H
H
H
H
H
4
15
14
33
42
55
23g
17/6h
42
k
l
OCH2O
1
1
Me
H
H
H
10
5j
20
OMe
OMe
58
a
b
d
On the basis of transformed starting material. Isolated as a mixture with 2. c Two stereoisomers; cis/trans ratio 1.3/1. R3 ) CH3.
e R3 ) C2H5. f R3 ) CH3/R3 ) H 17/4. Isolated with 5j (X ) OR ) OH). 5j: X, OR ) OCH2O, 17%; X ) OR ) OH, 6%. Unidentified
product ∼2%. Isolated as a mixture with 7k .
g
h
i
j
Sch em e 2
F igu r e 1. Fluorescence spectra of 1,3-dimethoxybenzene in
(detection limit 5-10%). These results indicate that
the presence (A) and the absence (N) of acid.
intermediacy of cyclohexadienone-like intermediates and
the mechanism of Scheme 2 are improbable.
The need for an acidic medium to allow a [2 + 2]
photocycloaddition was evident from the following obser-
vation: a very slow photoreaction of 1f and a less
selective formation of the expected products was detected
in neutral methanol and an increase of the conversion
was observed in the presence of increasing amounts of
sulfuric acid, according to Figure 3.
Formation of the final products can be explained
through acid-catalyzed processes and rearrangements, as
summarized in Scheme 3.
In order to obtain more information on the origin of
the observed photoreactivity, we examined the influence
of the ethylenic bond and of acidic conditions on the
fluorescence spectra of dialkoxybenzene derivatives. The
results are reported in Figures 1 and 2. Only a small
quenching of the fluorescence was observed at an H2SO4
concentration of 0.1 mol‚L-1. Furthermore, no significant
difference was observed for 1,3-dimethoxybenzene (Fig-
ure 1) and 1f (Figure 2), and within the described
concentration range, the presence of acid had no influence
on the UV spectra.
Intramolecular [2 + 2] photocycloaddition of the alkene
moiety onto the aromatic ring is regioselective and leads
to tricyclic and protonated isomers 2′ and 3′. Ring
opening of the protonated tetrahydrofuran moiety of 2′
We next considered the possibility of an initial [2 + 2]
photocycloaddition on an O-protonated dialkoxybenzene.

Bichromophoric Alkenyloxy Phenols and Benzenes
J . Org. Chem., Vol. 62, No. 20, 1997 6955
pathway producing small amounts of 3 (runs 4 and 5),
an opening of the cyclobutane ring leads to rearranged
products. A C-C bond between the benzene ring and
the unsaturated chain replaces the original and vinylic
C-O bond (path b). Depending on the deprotonation
process, and by intra- or intermolecular trapping of the
tertiary carbocation intermediate 4′, products 7, 6, and
8 are formed, respectively. From resorcinol diethers 1f
and 1g with a terminal alkene, products 4 and 5 can be
explained only if we assume that a C-C bond between
the benzene ring and ω-carbon of the alkenyloxy group
replaces the vinylic O-C3 bond of the starting material.
Rearrangement of 3′ with cyclobutane contraction and
formation of spiranic cyclopropylcarbinyl carbocation 5′ 13
could explain the formation of products 4 and 5 (path c).
That 4 and 5 could not be isolated from the corresponding
(alkenyloxy)phenols (runs 1-5) is indicative of a higher
preference of path a in the presence of a 1-hydroxyl group.
The unexpected photoreactivity of resorcinol diethers
led us to compare their reactivity with the corresponding
trihydroxybenzene derivatives 1i, 1j, and 1l. Two main
differences between resorcinol and trihydroxybenzene
derivatives were observed. No benzocyclobutene was
detected, but rearranged products 4 and 5 could be
isolated in high yield from 1i and 1l (runs 12 and 16).
Second, and unexpectedly, reduction product 9 could also
be isolated in yields up to 20% (run 16).
In acetonitrile an increase of the chemical yield of the
tetrahydrofuranyl derivative 5 should be observed. As
expected, the formation of 5j, resulting from an intramo-
lecular trapping of the cationic intermediate by the
terminal hydroxyl group, was favored when intermolecu-
lar trapping was impossible under these conditions (runs
9, 10, 13, and 14). Products 4 and 5 were not observed
from (alkenyloxy)phenols 1a -e, as well as when the
alkenyl side chain of 1h and 1k was substituted in the
terminal position (runs 1-5, 11, and 15). Furthermore,
4 and 5 were the sole products when an additional
alkyloxy substituent was present in the para position of
the butenyloxy or pentenyloxy side chain of ω-(alkenyl-
oxy)benzenes (runs 12, 13, and 14).
F igu r e 2. Fluorescence spectra of 1f in the presence (A) and
the absence (N) of acid.
From the observed results, it can be concluded that the
respective stability of the cationic intermediates, which
can be formed from an opening of the primary cycload-
ducts, is steering the reaction mixture (Scheme 4). When
R1 ) X ) H, no stabilized carbocation can be expected
from an opening of the cyclobutane ring, and deprotona-
tion through path a is the preferred process. When R1
is an alkyl group, cleavage of a cyclobutane bond which
leads to a tertiary cation competes favorably with the
deprotonation process (path b). From starting com-
pounds 1i-l, bearing one additional alkoxy group on the
benzene ring, rearrangement of intermediate 2′ can
produce 5′, stabilized by the electron-donating ability of
X. In absence of alkyl substituents (R1 ) H), formation
of 5′ and then of 4 and 5 is now preferred to the other
processes.
F igu r e 3. Dependence of the conversion of 1f from pH after
2.5 h of irradiation.
and 3′ involves the breaking of a C-O bond. Rearoma-
tization by deprotonation of the system according to path
a describes the formation of benzocyclobutenes 2 and 3.
The regioselectivity of the benzocyclobutene formation
was found to be higher with diethers 1f and 1g (runs
6-10) than with the corresponding (alkenyloxy)phenols
1a , 1b, and 1c (entries 1-3). This change might reflect
a difference in steric hindrance between the hydroxy or
the methoxy substituent and a preference for a bond-
forming step at the para rather than the ortho position.
When R1 is an alkyl group and when the alkenyl chain
is trisubstituted, two rearomatization processes now
compete (runs 4, 5, 11, and 15). Besides a deprotonation
Formation of rearranged compounds 9 (entries 15 and
16) was very surprising and involves a reduction step.
(13) For the discussion of similar intermediates in ground state and
photochemical reactions, see: (a) Miller, B. Acc. Chem. Res. 1975, 8,
345-358. (b) Schuster, D.; Polowczyk, C. J . J . Am. Chem. Soc. 1964,
86, 4502-4503. (c) Schuster, D.; Polowczyk, C. J . J . Am. Chem. Soc.
1966, 88, 1722-1731. (d) Pirkle, W. H.; Smith, S. G.; Koser, G. F. J .
Am. Chem. Soc. 1969, 91, 1580-1582. (e) Schulz, A. G.; Taveras, A.
G. Tetrahedron Lett. 1996, 37, 5853-5856. (f) Olah, G. A. Namanworth,
E.; Comisarow, M.; Ramsey, B. J . Am. Chem. Soc. 1967, 89, 711-713.
(g) Olah, G. A. Angew. Chem., Int. Ed. Engl. 1995, 34, 1393-1405.

6956 J . Org. Chem., Vol. 62, No. 20, 1997
Hoffmann and Pete
Sch em e 3. Mech a n ism for th e F or m a tion of Differ en t P r od u cts in th e Rea ction of 3-(Alk en yloxy)p h en ols
a n d (Alk en yloxy)(a lk yloxy)ben zen e Der iva tives in Acid ic Med ia
mixture was stirred at 80 °C for 2 h. Most of the DMF was
then evaporated, and the residue was treated with water and
ether. The aqueous phase was extracted twice with ether. The
combined organic phases were dried over MgSO4. After
evaporation of the ether, the crude material was purified by
flash silicagel chromatography (eluent, petroleum ether and
ethyl acetate). For the preparation of the (alkenyloxy)phenols,
resorcinol was added in excess (82 mmol) in order to reduce
the proportion of the bisalkylated product in the presence of
K2CO3 (15 g) and 70 mL of DMF (70 mL). After extraction of
the alkaline mixture with ether, the aqueous phase was
carefully acidified with concentrated HCl and extracted again
with ether (3×).
Sch em e 4
Although we have verified that 9 is not obtained from a
reduction of 8 under the reaction conditions, further
experiments are still needed to explain its formation.
3-(Bu t-3-en yloxy)p h en ol (1a ). Yield: 48%. Yield of di-
alkylated product: 23%. UV: λmax (ꢀ) ) 205 (18400), 220
(7000), 275 (2200) nm. 1H NMR (250 MHz, CDCl3): δ 7.10
(1H, t, J ) 8.5), 6.4-6.5 (3H, m), 5.88 (1H, ddt, J ) 10, 17,
6.5), 5.05-5.20 (2H, m), 3.95 (2H, t, J ) 7.5), 2.51 (2H, qt, J
) 6.5, 1.5). 13C NMR (62 MHz, CDCl3): δ 160.20, 156.93,
134.36, 130.05, 116.96, 107.92, 106.96, 102.25, 67.26, 33.53.
IR (film): ν 3374, 3073, 2936, 1591, 1491, 1290, 1154. MS
m/ z (rel intensity): 164 (M+, 55), 136 (14), 123 (18), 120 (15),
118 (15), 111 (14), 110 (100). HRMS m/ z calcd for C10H12O2:
164.0837, found 164.0840.
3-(P en t-4-en yloxy)p en ol (1b). Yield: 38%. Yield of the
dialkylated product: 30%. 1H NMR (250 MHz, CDCl3): δ 7.11
(1H, t, J ) 8.0), 6.37-6.52 (3H, m), 5.85 (1H, ddt, J ) 10.0,
17.0, 6.5), 4.95-5.10 (2H, m), 3.94 (2H, t, J ) 7), 2.22 (2H, q,
J ) 7), 1.87 (2H, p, J ) 7). 13C NMR (62 MHz, CDCl3): δ
160.46, 156.71, 137.79, 130.09, 115.17, 107.68, 107.13, 102.14,
67.26, 30.07, 28.38. IR (film): ν 3399, 3073, 2948, 1591, 1491,
1291, 1140. MS m/ z (rel intensity): 178 (M+, 100), 123 (11),
111 (42), 110 (65), 93 (14), 82 (20), 81 (29), 69 (47). HRMS
m/ z calcd for C11H14O2: 178.0994, found 178.0990.
Con clu sion
In contrast to the very slow transformation observed
when the reaction was carried out in neutral conditions,
benzocyclobutenes 2 and 3 and rearranged products 4-
9 were obtained when 1 was irradiated in acidic media
at λ ) 254 nm. Formation of the reaction products can
be explained by a sequence initiated by a [2 + 2]
cycloaddition and followed by an acid-catalyzed rearo-
matization of the corresponding intermediates.
Further work to determine the limits of this photore-
activity and to apply the benzocyclobutenes to the
synthesis of natural products analogs are now in progress.
Exp er im en ta l Section
Syn th esis of Com p ou n d s 1. Phenol (45 mmol) and the
corresponding alkenyl tosylate (45 mmol) were dissolved in
DMF (50 mL) followed by the addition of K2CO3 (15 g). The

Bichromophoric Alkenyloxy Phenols and Benzenes
J . Org. Chem., Vol. 62, No. 20, 1997 6957
3-((3-Meth ylbu t-3-en yl)oxy)pen ol (1c). Yield: 38%. Yield
of the dialkylated product: 34%. 1H NMR (250 MHz, CDCl3):
δ 7.10 (1H, t, J ) 8.5), 6.38-6.52 (3H, m), 5.22 (1H, s), 4.83
(1H, s), 4.78 (1H, s), 4.04 (2H, t, J ) 7), 2.48 (2H, t, J ) 7),
1.80 (3H, s). 13C NMR (62 MHz, CDCl3): δ 160.23, 156.73,
142.12, 130.09, 111.97, 107.84, 107.08, 102.23, 66.53, 37.10,
22.76. IR (film): ν 3399, 3073, 2936, 1591, 1505, 1290, 1154.
MS m/ z (rel intensity): 178 (M+, 77), 150 (12), 123 (15), 111
(33), 110 (100), 93 (15), 87 (15), 85 (74), 83 (94), 69 (40). HRMS
m/ z calcd for C11H14O2: 178.0994, found 178.0976.
3-((4-Metylp en t-3-en yl)oxy)p h en ol (1d ). Yield: 36%.
Yield of the dialkylated product: 11%. 1H NMR (250 MHz,
CDCl3): δ 7.12 (1H, t, J ) 8.5), 6.40-6.55 (3H, m), 5.55 (1H,
s), 5.16-5.27 (1H, m), 4.78 (2H, m), 3.91 (2H, t, J ) 7), 2.47
(2H, q, J ) 7), 1.75 (3H, s), 1.67 (3H, s). 13C NMR (62 MHz,
CDCl3): δ 160.24, 156.67, 134.44, 130.06, 119.48, 107.77,
107.06, 102.17, 67.73, 28.14, 25.69, 17.81. IR (film): ν 3387,
2973, 2923, 2872, 1591, 1491, 1291, 1154. MS m/ z (rel
intensity): 192 (M+, 100), 165 (35), 151 (15), 149 (16), 136 (10),
124 (17), 123 (55), 121 (17), 112 (40), 111 (63), 110 (63). HRMS
m/ z calcd for C12H16O2: 192.1150, found 192.1170.
2.28 (2H, m), 1.85 (2H, tt, J ) 6.5, 7.5). 13C NMR (62 MHz,
CDCl3): δ 154.63, 148.22, 141.54, 137.82, 115.11, 107.90,
105.80, 101.04, 98.13, 68.20, 30.08, 28.48. IR (film): ν 3079,
2880, 2774, 1634, 1473, 1186, 1040. MS m/ z (rel intensity):
206 (M+, 40), 192 (30), 139 (15), 138 (100), 137 (75), 121 (8),
107 (17). HRMS m/ z calcd for C12H14O3: 206.0943, found
206.0933.
5-((3-Met h ylb u t -3-en yl)oxy)b en zo[1,3]d ioxole
(1k ).
Yield: 57%. 1H NMR (250 MHz, CDCl3): δ 6.69 (1H, d, J )
8.5), 6.49 (1H, d, J ) 2.5), 6.33 (1H, dd, J ) 8.5, 2.5), 5.90
(2H, s), 5.19 (1H, t/sep, J ) 7, 1.5), 3.85 (2H, t, J ) 7), 2.44
(2H, q, J ) 7), 1.73 (3H, s), 1.65 (3H, s). 13C NMR (62 MHz,
CDCl3): δ 154.57, 148.21, 141, 134.30, 119.63, 107.90, 105.83,
101.04, 98.16, 68.67, 28.30, 17.82. IR (film): ν 2973, 2880,
1630, 1190, 1040. MS m/ z (rel intensity): 220 (M+, 25), 139
(15), 138 (100), 137 (30), 121 (7), 107 (7). HRMS m/ z calcd
for C13H16O3: 220.1099, found 220.1103.
3-(Bu t-3-en yloxy)-1,6-d im eth oxyben zen e (1l). Yield:
69%. 1H NMR (250 MHz, CDCl3): δ 6.77 (1H, d, J ) 8.5),
6.52 (1H, d, J ) 2.5), 6.41 (1H, dd, J ) 8.5, 2.5), 5.91 (2H, s),
5.90 (1H, ddt, J ) 17, 10, 6.5), 5.08-5.22 (2H, m), 3.97 (2H, t,
J ) 6.5), 3.85 (3H,s), 3.83 (3H, s), 2.53 (2H, tq, J ) 1.5, 6.5).
13C NMR (62 MHz, CDCl3): δ 153.60, 149.95, 143.59, 134.50,
116.85, 112.09, 104.05, 101.14, 67.79, 55.49, 55.80, 33.70. IR
(film): ν 3075, 2936, 2836, 1597, 1516, 1229, 1028. MS m/ z
(rel intensity): 208 (M+, 100), 182 (11), 167 (6), 154 (98), 139
(88), 125 (22), 120 (18), 118 (18), 111 (21). HRMS m/ z calcd
for C12H16O3: 208.1099, found 208.1109.
3-((4-Eth ylh ex-3-en yl)oxy)p h en ol (1e). Yield: 30%. 1H
NMR (250 MHz, CDCl3): δ 7.12 (1H, t, J ) 8), 6.51 (1H, ddd,
J ) 0.7, 2.5, 8), 6.40-6.46 (2H, m), 5.20 (1H, s), 5.15 (2H, t, J
) 7), 3.91 (2H, t, J ) 7), 2.50 (2H, q, J ) 7), 2.00-2.15 (4H,
m), 1.02 (3H, t, J ) 7), 1.00 (1H, t, J ) 7). 13C NMR (62 MHz,
CDCl3): δ 160.36, 156.70, 145.77, 130.06, 117.35, 107.68,
107.06, 102.16, 67.98, 29.16, 27.71, 23.32, 13.20, 12.72. IR
(film): ν 3387, 2961, 2872, 1591, 1491, 1291, 1140. MS m/ z
(rel intensity): 220 (M+, 60), 179 (18), 165 (21), 149 (10), 136
(13), 123 (20), 111 (100), 110 (38), 95 (30), 81 (45). HRMS m/ z
calcd for C14H20O2: 220.1463, found 220.1456.
3-(Bu t-3-en yloxy)-1-m eth oxyben zen e (1f). Yield: 61%.
UV: λmax (ꢀ) ) 205 (25000), 220 (8000), 275 (2200) nm. 1H
NMR (250 MHz, CDCl3): δ 7.15 (1H, t, J ) 8), 6.44-6.52 (3H,
m), 5.89 (1H, ddt, J ) 17, 10, 7), 5.06-5.21 (2H, m), 3.99 (2H,
t, J ) 7), 3.77 (3H, s), 2.52 (2H, q, J ) 6.5). 13C NMR (62
MHz, CDCl3): δ 160.90, 160.21, 134.45, 129.81, 116.95, 106.80,
106.36, 101.14, 67.23, 55.21, 33.61. IR (film): ν 3079, 2936,
2836, 1605, 1491, 1291, 1154. MS m/ z (rel intensity): 178
(M+, 52), 150 (7), 137 (24), 124 (100), 107 (28). HRMS m/ z
calcd for C11H14O2: 178.0994, found 178.1007.
1-Meth oxy-3-(pen t-4-en tyloxy)ben zen e (1g). Yield: 79%.
1H NMR (250 MHz, CDCl3): δ 7.16 (1H, t, J ) 8), 6.45-6.52
(3H, m), 5.85 (1H, ddt, J ) 17, 10, 6.5), 4.95-5.11 (2H, m),
3.95 (2H, t, J ) 6.5), 3.78 (3H, s), 2.18-2.29 (2H, m), 1.81-
1.94 (2H, m). 13C NMR (62 MHz, CDCl3): δ 160.89, 160.37,
137.82, 129.81, 115.13, 106.80, 106.20, 101.09, 67.21, 55.24,
30.11, 28.46. IR (film): ν 3073, 2936, 2836, 1605, 1491, 1291,
1154. MS m/ z (rel intensity): 192 (M+, 40), 125 (29), 124
(100), 107 (8). HRMS m/ z calcd for C12H16O2: 192.1150, found
192.1121.
1-Meth oxy-3-((4-m eth ylp en t-3-en yl)oxy)ben zen e (1h ).
Yield: 42%. 1H NMR (250 MHz, CDCl3): δ 7.15 (1H, dt, J )
1, 8), 6.44-6.53 (3H, m), 5.20 (1H, d/sep, J ) 7, 1.5), 3.91 (2H,
t, J ) 7), 3.78 (3H, s), 2.43 (1H, q, J ) 7), 1.73 (3H, d, J )
1.5), 1.65 (3H, d, s). 13C NMR (62 MHz, CDCl3): δ 160.78,
160.24, 134.32, 129.74, 119.74, 106.68, 106.18, 100.97, 61.23,
55.18, 28.20, 25.66, 17.78. IR (film): ν 2922, 1591, 1491, 1291.
MS m/ z (rel intensity): 206 (M+, 12), 137 (10), 125 (64), 124
(100), 111 (12), 107 (18). HRMS m/ z calcd for C11H14O2:
206.1307, found 206.1324.
Ir r a d ia tion of Com p ou n d s 1a -l. Solutions (16 mL) of
0.5 mmol of 1 and 0.1 mmol of H
2SO4 were irradiated at λ )
254 nm (Rayonet, T ) 35 °C). After 4 h, the reaction was
stopped and NaHCO3 was added to the solution. After
evaporation of the solvent, the residue was purified by flash
silica gel chromatography with petroleum ether/ethyl acetate.
8-(2-Hydr oxyeth yl)bicyclo[4.2.0]octa-1,3,5-tr ien -3-ol (2a).
1H NMR (250 MHz, CD3COCD3): δ 7.9 (1H,s), 6.83 (1H, d, J
) 8), 6.60-6.68 (2H, m), 3.65-3.76 (3H, m), 3.40-3.55 (1H,
m), 3.18 (1H, dd, J ) 5.5, 13.5), 2.64 (1H, dd, J ) 2.5, 13.5),
1.87 (2H, q, J ) 6.5). 13C NMR (62 MHz, CD3COCD3):
δ
157.59, 151.03, 134.33, 124.52, 115.23, 110.40, 61.43, 40.29,
38.52, 35.50. IR (KBr): ν 3387, 3048, 2923, 1591, 1454, 1366,
1015. MS m/ z (rel intensity): 164 (M+, 74), 145 (30), 133
(100), 131 (53), 120 (37), 115 (46), 107 (40), 105 (80), 103 (42).
HRMS m/ z calcd for C10H12O2: 164.0837, found 164.0825.
7-(2-Hydr oxyeth yl)bicyclo[4.2.0]octa-1,3,5-tr ien -2-ol (3a).
1H NMR (250 MHz, CD3COCD3): δ 7.05 (1H, t, J ) 8.5). 13C
NMR (62 MHz, CD3COCD3): δ 129.30, 114.83, 114.50, 40.59,
34.59.
8-(3-H yd r oxyp r op yl)b icyclo[4.2.0]oct a -1,3,5-t r ien -3-
ol (2b). 1H NMR (250 MHz, CD3COCD3): δ 8.0 (1H,s), 6.85
(1H, d, J ) 7.5), 6.57-6.70 (2H, m), 3.55-3.75 (3H, m), 3.16
(1H, m), 3.10-3.27 (2H, m), 2.58 (1H, t, J ) 13), 1.65-1.78
(4H, m) 13C NMR (62 MHz, CD3COCD3): δ 157.54, 151.33,
134.23, 124.54, 115.20, 110.22, 62.51, 43.08, 35.41, 32.13,
31.63. IR (film): ν 3324, 2924, 2851, 1591, 1466, 1253, 1053.
MS m/ z (rel intensity): 178 (M+, 55), 163 (19), 161 (10), 159
(8), 147 (74), 145 (40), 134 (33), 133 (60), 132 (100), 131 (40),
127 (19), 121 (25), 119 (27), 117 (16), 115 (32), 107 (40), 105
(35), 103 (23). HRMS m/ z calcd for C11H14O2: 178.0994, found
178.0972.
7-(3-H yd r oxyp r op yl)b icyclo[4.2.0]oct a -1,3,5-t r ien -2-
ol (3b). 1H NMR (250 MHz, CD3COCD3): δ 8.30 (1H, s), 7.01
(1H, t, J ) 8), 2.64 (1H, d, J ) 12.5). 13C NMR (62 MHz,
CD3COCD3): δ 129.24, 127.84, 114.82, 114.34, 62.51, 43.42,
34.50.
8-(2-H yd r oxyet h yl)-8-m et h ylb icyclo[4.2.0]oct a -1,3,5-
tr ien -3-ol (2c). 1H NMR (250 MHz, CD3COCD3): δ 7.93
(1H,s), 6.85 (1H, d, J ) 8), 6.64 (1H, dd, J ) 8, 2.5), 6.59 (1H,
d, J ) 2.5), 3.64 (2H, q, J ) 6.5), 3.42 (1H, t, J ) 5), 2.95 (1H,
d, J ) 13), 2.72 (1H, d, J ) 13), 1.92 (1H, t, J ) 6.5), 1.91 (1H,
t, J ) 6.5), 1.37 (3H, s). 13C NMR (62 MHz, CD3COCD3): δ
157.54, 155.08, 132.04, 125.22, 115.49, 113.87, 109.08, 60.23,
43.26 (2), 35.41, 24.91. IR (film): ν 3349, 2953, 2921, 1597,
1466, 1366, 1265, 1204, 1053. MS m/ z (rel intensity): 178
(M+, 65), 163 (30), 160 (50), 147 (69), 145 (100), 135 (22), 133
(37), 132 (50), 131 (46), 121 (22), 119 (27), 117 (50), 115 (35),
5-(Bu t-3-en yloxy)ben zo[1,3]d ioxole (1i). Yield: 50%. 1H
NMR (250 MHz, CDCl3): δ 6.70 (1H, d, J ) 8.5), 6.51 (1H, d,
J ) 2.5), 6.34 (1H, dd, J ) 8.5, 2.5), 5.91 (2H, s), 5.90 (1H,
ddt, J ) 16.5, 10, 6.5), 5.05-5.22 (2H, m), 3.95 (2H, t, J ) 7),
2.52 (2H, tq, J ) 1.5, 7). 13C NMR (62 MHz, CDCl3): δ 154.46,
141.65, 134.47, 121.33, 116.92, 107.90, 105.92, 101.07, 98.25,
68.27, 33.67. IR (film): ν 3073, 2886, 2772, 1630, 1491, 1190,
1040. MS m/ z (rel intensity): 192 (M+, 45), 138 (100), 137
(53), 107 (12). HRMS m/ z calcd for C11H12O3: 192.0786, found
192.0772.
5-(P en t-4-en yloxy)ben zo[1,3]d ioxole (1j). Yield: 72%.
1H NMR (250 MHz, CDCl3): δ 6.68 (1H, d, J ) 8), 6.49 (1H, d,
J ) 2.5), 6.32 (1H, dd, J ) 8, 2.5), 5.90 (2H, s), 5.85 (1H, ddt,
J ) 17, 10, 6.5), 4.95-5.11 (2H, m), 3.89 (2H, t, J ) 6.5), 2.15-

6958 J . Org. Chem., Vol. 62, No. 20, 1997
Hoffmann and Pete
107 (66), 105 (25), 103 (27). HRMS m/ z calcd for C11H14O2:
178.0994, found 178.0995.
7-(2-H yd r oxyet h yl)-7-m et h ylb icyclo[4.2.0]oct a -1,3,5-
tr ien -2-ol (3c). 1H NMR (250 MHz, CD3COCD3): δ 8.2 (1H,
s), 7.01 (1H, t, J ) 7.5). 13C NMR (62 MHz, CD3COCD3): δ
46.57.
6.82 (3H, m), 3.68-3.80 (3H, s), 3.59 (1H, dq, J ) 9, 7), 2.94
(1H, dd, J ) 13.5, 5.5), 2.76 (1H, s), 2.68 (1H, dd, J ) 13.5, 7),
1.60-1.80 (2H, m), 1.18 (3H, t, J ) 7). 13C NMR (62 MHz,
CDCl3): δ 159.53, 140.01, 129.21, 121.76, 115.22 111.37, 80.47,
64.84, 60.91, 55.06, 55.10, 40.53, 35.93, 15.48.
3-H yd r oxy-4-(3-m et h oxyp h en yl)b u t a n -1-ol (4f) (R3
)
H). 1H NMR (250 MHz, CDCl3): δ 7.22 (1H, dt, J ) 1.5, 7.5),
6.74-6.83 (3H, m), 4.02-4.14 (1H, m), 3.75-3.93 (2H, m), 3.79
(3H, s), 2.78 (1H, dd, J ) 14, 5.5), 2.77 (1H, dd, J ) 8, 14),
2.35 (2H, s), 1.65-1.85 (2H, m). 13C NMR (62 MHz, CDCl3):
δ 159.80, 139.61, 129.56, 121.67, 115.13 111.91, 72.74, 61.53,
55.12, 44.35, 37.87.
8,8-Dim eth yl-7-(2-h ydr oxyeth yl)bicyclo[4.2.0]octa-1,3,5-
tr ien -2-ol (3d ). 1H NMR (250 MHz, CD3COCD3): δ 7.9 (1H,s),
6.97 (1H, dd, J ) 7.5, 8.5), 6.61 (1H, d, J ) 7.5), 6.59 (1H, d,
J ) 8.5), 3.70-3.82 (3H, m), 3.10 (1H, t, J ) 7.5), 1.85-1.97
(1H, m), 1.65-1.80 (1H, m), 1.45 (3H, s), 1.34 (3H, s). 13C NMR
(62 MHz, CD3COCD3): δ 151.60, 148.62, 129.13, 115.32,
114.95, 61.75, 51.68, 46.58, 34.12, 27.51, 21.91. IR (KBr): ν
3438, 3148, 2948, 1593, 1454, 1263, 1014. MS m/ z (rel
intensity): 192 (M+, 24), 177 (19), 161 (17), 159 (50), 147 (52),
135 (30), 133 (100), 131 (70), 128 (22), 121 (23), 115 (32), 110
(22), 107 (39), 105 (22), 103 (17). HRMS m/ z calcd for
C12H16O2: 192.1150, found 192.1155.
8,8-Dieth yl-7-(2-h yd r oxyeth yl)bicyclo[4.2.0]octa -1,3,5-
tr ien -2-ol (3e). 1H NMR (250 MHz, CD3COCD3): δ 7.9 (1H,s),
6.83 (1H, dd, J ) 7.5, 8.), 6.43-6.52 (2H, m), 3.59-3.70 (2H,
m), 3.54 (1H, t, J ) 5), 3.02 (1H, dd, J ) 5.5, 10), 1.42-1.88
(6H, m), 0.96 (3H, t, J ) 7.5), 0.78 (3H, t, J ) 7.5). 13C NMR
(62 MHz, CD3COCD3): δ 151.95, 149.63, 136.58, 128.97,
115.29, 114.76, 61.92, 55.41, 49.33, 33.80, 25.85, 10.36, 9.89.
IR (KBr): ν 3538, 3212, 2961, 2880, 1591, 1455, 1291, 1010.
MS m/ z (rel intensity): 220 (M+, 37), 191 (20), 176 (29), 173
(60), 161 (50), 159 (37), 147 (100), 145 (96), 133 (48), 131 (43),
128 (40), 119 (16), 117 (25), 115 (50), 107 (33), 105 (22), 103
(13). HRMS m/ z calcd for C14H20O2: 220.1463, found 220.1461.
8-(2-Hyd r oxyeth yl)-3-m eth oxybicyclo[4.2.0]octa -1,3,5-
tr ien e (2f). 1H NMR (250 MHz, CDCl3): δ 7.99 (1H, d, J )
8), 6.78 (1H, dd, J ) 8, 2), 6.72 (1H, d, J ) 2), 3.82 (2H, t, J )
7), 3.78 (3H, s), 3.48-3.60 (1H, m), 3.10 (1H, dd, J ) 5, 13),
2.73 (1H, dd, J ) 13, 2.5), 1.99 (2H, q, J ) 7), 1.8 (1H, s). 13C
NMR (62 MHz, CDCl3): δ 159.18, 149.69, 135.07, 123.92, 113.
65, 108.08, 61.66, 55.41, 39.34, 37.12, 35.02. IR (film): ν 3349,
2923, 2836, 1605, 1476, 1273, 1167, 1030. MS m/ z (rel
intensity): 178 (M+, 49), 163 (11), 159 (10), 149 (23), 147 (100),
145 (15), 135 (20), 132 (23), 122 (22), 117 (24), 115 (44), 107
(17), 104 (27), 103 (32). HRMS m/ z calcd for C11H14O2:
178.0934, found 178.0970.
7-(2-Hyd r oxyeth yl)-2-m eth oxybicyclo[4.2.0]octa -1,3,5-
tr ien e (3f). 1H NMR (250 MHz, CDCl3): δ 7.14 (1H, t, J )
7.5), 3.88 (3H, s), 2.90 (1H, dd, J ) 2, 13), 2.00 (2H, q, J ) 7).
13C NMR (62 MHz, CDCl3): δ 128.55, 114.66, 113.10, 55.99,
40.19, 35.68.
8-(3-Hydr oxypr opyl)-3-m eth oxybicyclo[4.2.0]octa-1,3,5-
tr ien e (2g). 1H NMR (250 MHz, CDCl3): δ 6.95 (1H, d, J )
8), 6.73 (1H, dd, J ) 8, 2.5), 6.66-6.71 (1H, m), 3.75 (3H, s),
3.62-3.70 (2H, m), 3.33-3.46 (1H, m), 3.23 (1H, dd, J ) 13.5,
5), 2.65 (1H, dd, J ) 13.5, 2.5), 2.0 (1H, s), 1.70-1.80 (4H, m).
13C NMR (62 MHz, CDCl3): δ 159.08, 150.09, 135.07, 123.86,
113.50, 107.96, 62.68, 55.37, 42.28, 34.99, 31.14, 30.42. IR
(film): ν 3399, 2932, 2851, 1604, 1480, 1271, 1167, 1057. MS
m/ z (rel intensity): 192 (M+, 100), 177 (44), 161 (87), 159 (39),
148 (46), 147 (76), 146 (74), 135 (40), 131 (42), 121 (51), 115
(48), 105 (28), 103 (48). HRMS m/ z calcd for C12H16O2:
192.1150, found 192.1135.
4-Meth oxy-5-(3-m eth oxyp h en yl)p en ta n -1-ol (4g). 1H
NMR (250 MHz, CDCl3): δ 7.19 (1H, dd, J ) 7.5, 8.5), 6.70-
6.81 (3H, m) 3.78 (3H, s), 3.58 (2H, t, J ) 6), 3.35-3.46 (1H,
m), 3.33 (3H, s), 2.87 (1H, dd, J ) 14, 6), 2.66 (1H, dd, J ) 14,
7), 2.40 (1H, s), 1.41-1.78 (4H, m). 13C NMR (62 MHz,
CDCl3): δ 159.46, 140.29, 129.12, 121.67, 115.14 111.25, 82.14,
62.63, 56.78, 55.99, 39.84, 29.99, 28.51. IR (film): ν 3399,
2936, 1603, 1489, 1262, 1154, 1055. MS m/ z (rel intensity):
244 (M+, 21), 192 (96), 165 (31), 161 (38), 147 (32), 138 (30),
122 (100), 121 (73), 115 (24), 107 (22), 105 (27), 103 (97).
HRMS m/ z calcd for C13H20O3: 224.1412, found 224.1441.
4-(Ben zo[1,3]d ioxol-5-yl)-3-m eth oxybu ta n -1-ol (4i). 1H
NMR (250 MHz, C6D6): δ 6.67 (1H, d, J ) 1.5), 6.64 (1H, d, J
) 8), 6.49 (1H, dd, J ) 1.5, 8), 5.40 (2H, s), 3.64 (1H, dt, J )
11, 6), 3.59 (1H, dt, J ) 11, 6), 3.36 (1H, p, J ) 6), 3.06 (3H,
s), 2.63 (1H, dd, J ) 6, 14), 2.50 (1H, s), 2.47 (1H, dd, J ) 6,
14), 1.55 (2H, q, J ) 6). 13C NMR (62 MHz, C6D6): δ 148.08,
146.47, 132.81, 122.70, 110.21, 108.31, 100.81, 81.27, 60.04,
56.65, 39.85, 36.44. IR (film): ν 3399, 2934, 2890, 1608, 1491,
1246, 1040. MS m/ z (rel intensity): 244 (M+, 12), 206 (35),
192 (17), 138 (100), 137 (45), 135 (42), 118 (10), 116 (11), 107
(10). HRMS m/ z calcd for C12H16O4: 224.1049, found 224.1049.
5-(Ben zo[1,3]dioxol-5-yl)-4-m eth oxypen tan -1-ol (4j). 1H
NMR (250 MHz, CDCl3): δ 6.71 (1H, d, J ) 7.5), 6.69 (1H, d,
J ) 1.5), 6.63 (1H, dd, J ) 1.5, 7.5), 5.93 (2H, s), 3.60 (2H, t,
J ) 6), 3.23-3.41 (1H, m), 3.33 (3H, s), 2.80 (1H, dd, J ) 6,
14), 2.62 (1H, dd, J ) 7, 14), 2.49 (1H, s), 1.40-1.71 (4H, m).
13C NMR (62 MHz, CDCl3): δ 147.43, 145.81, 132.31, 122.14,
109.62, 108.02, 100.69, 82.32, 62.71, 56.83, 39.34, 29.91, 28.49.
4-(3,4-Dim eth oxyp h en yl)-3-m eth oxybu ta n -1-ol (4l). 1H
NMR (250 MHz, CDCl3): δ 6.70-6.83 (3H, m), 3.87 (3H, s),
3.85 (3H, s), 3.70-3.79 (2H, m), 3.52-3.65 (1H, m), 2.90 (1H,
dd, J ) 6, 14), 2.65 (1H, dd, J ) 7, 14), 2.35 (1H, s, broad),
1.59-1.81 (2H, m). 13C NMR (62 MHz, CDCl3): δ 148.80,
147.54, 130.88, 121.33, 112.73, 111.28, 82.11, 60.72, 57.03,
55.83 (2), 39.39, 35.68. IR (film): ν 3426, 2936, 2836, 1591,
1520, 1265, 1142. MS m/ z (rel intensity): 240 (M+, 67), 195
(13), 165 (10), 152 (40), 151 (100), 138 (15), 137 (15), 120 (17),
118 (17), 107 (17). HRMS m/ z calcd for C13H20O4: 240.1362,
found 240.1365.
2-(3-Meth oxyben zyl)tetr a h yd r ofu r a n (5g). 1H NMR
(250 MHz, CDCl3): δ 7.19 (1H, t, J ) 8), 6.7-6.85 (3H, m),
4.06 (1H, p, J ) 6.5), 3.83-3.94 (1H, m), 3.78 (3H, s), 3.67-
3.77 (1H, m), 3.89 (1H, dd, J ) 13.5, 6.5), 1.75-2.00 (3H, m),
1.47-1.62 (1H, m).
13C NMR (62 MHz, CDCl3): δ 159.51,
140.49, 129.15, 121.53, 114.90, 111.40, 79.85, 67.83, 55.00,
41.88, 30.93, 25.51. IR (film): ν 3426, 2944, 2867, 1603, 1489,
1260, 1061. MS m/ z (rel intensity): 192 (M+, 100), 181 (7),
169 (6), 147 (7), 134 (11), 131 (12), 124 (79), 122 (42), 121 (62),
115 (11), 107 (14), 103 (9). HRMS m/ z calcd for C12H16O2:
192.1150, found 192.1170.
7-(3-Hydr oxypr opyl)-2-m eth oxybicyclo[4.2.0]octa-1,3,5-
tr ien e (3g). 1H NMR (250 MHz, CDCl3): δ 7.10 (1H, t, J )
8), 3.84 (3H, s). 13C NMR (62 MHz, CDCl3): δ 129.28, 114.54,
113.03, 55.95, 43.13, 35.67.
3-Met h oxy-4-(3-m et h oxyp h en yl)b u t a n -1-ol (4f) (R3
)
5-(Tetr a h yd r ofu r a n -2-ylm eth yl)ben zo[1,3]d ioxole (5j).
1H NMR (250 MHz, CDCl3): δ 6.63-6.75 (3H, m), 5.90 (2H,
s), 3.93-4.06 (1H, m), 3.82-3.93 (1H, m), 3.67-3.78 (1H, m),
2.80 (1H, dd, J ) 14, 6.5), 2.67 (1H, dd, J ) 14, 6), 1.77-1.98
(3H, m), 145-1.60 (1H, m). 13C NMR (62 MHz, CDCl3): δ
147.47, 145.85, 132.76, 121.96, 109.59, 108.03, 100.67, 80.04,
67.83, 41.50, 30.86, 25.54. IR (film): ν 2861, 1489, 1248, 1040.
MS m/ z (rel intensity): 206 (M+, 30), 192 (19), 138 (100), 137
(48), 135 (19), 107 (10). HRMS m/ z calcd for C12H14O3:
206.0943, found 206.0942.
Me). 1H NMR (250 MHz, CDCl3): δ 7.19 (1H, dd, J ) 7, 9),
6.71-6.81 (3H, m) 3.80 (3H, s), 3.70-3.79 (2H, m), 3.56-3.70
(1H, m), 3.39 (3H, s), 2.95 (1H, dd, J ) 13, 5.5), 2.68 (1H, dd,
J ) 13, 7), 2.65 (1H, s), 1.58-1.81 (2H, m). 13C NMR (62 MHz,
CDCl3): δ 159.61, 139.89, 129.29, 121.78, 115.31 111.40, 82.01,
60.76, 56.99, 55.10, 39.84, 35.74. IR (film): ν 3412, 2940, 2836,
1603, 1489, 1261, 1051. MS m/ z (rel intensity): 210 (M+, 100),
178 (32), 165 (34), 161 (48), 147 (47), 135 (42), 121 (94), 120
(69), 117 (19), 115 (30), 107 (26), 105 (31), 103 (27). HRMS
m/ z calcd for C12H18O3: 210.1255, found 210.1230.
2-(2,4-Dih yd r oxyben zyl)tetr a h yd r ofu r a n (5j) (X ) OR
) OH). 1H NMR (250 MHz, CDCl3): δ 6.58 (1H, dd, J ) 8,
2), 4.02 (1H, p, J ) 6.5), 3.81-3.93 (1H, m), 3.64-3.77 (1H,
3-Eth oxy-4-(3-m eth oxyp h en yl)bu ta n -1-ol (4f) (R3 ) Et).
1H NMR (250 MHz, CDCl3): δ 7.20 (1H, dd, J ) 7, 8.5), 6.72-

Bichromophoric Alkenyloxy Phenols and Benzenes
J . Org. Chem., Vol. 62, No. 20, 1997 6959
m), 2.61 (1H, dd, J ) 14, 6.5), 1.75-1.97 (3H, m). 13C NMR
(62 MHz, CDCl3): δ 144, 142.61, 130.97, 120.89, 115.98,
114.88, 80.25, 67.73, 41.06, 30.75, 25.44.
(3H, m), 4.93 (1H, s), 4.85 (1H,s), 3.78 (3H, s), 3.58 (2H, t, J )
6.5), 3.56 (1H, t, J ) 6.5), 3.38 (1H, t, J ) 7.5), 2.09 (1H, p, J
) 7), 1.89-2.02 (1H, m), 1.85 (1H, s), 1.59 (3H, s). 13C NMR
(62 MHz, CDCl3): δ 159.61, 147.56, 144.70, 129.18, 120.26,
113.75, 111.37, 110.47, 61.06, 55.05, 48.92, 35.70, 20.96. IR
(film): ν 3362, 2946, 2838, 1607, 1485, 1264, 1046. MS m/ z
(rel intensity): 206 (M+, 100), 175 (60), 173 (44), 161 (98), 160
(70), 147 (56), 135 (45), 129 (23), 121 (43), 115 (31), 105 (19).
HRMS m/ z calcd for C13H18O2: 206.1307, found 206.1306.
3-(Ben zo[1,3]d ioxol-5-yl)-4-m eth ylp en t-4-en -1-ol (7k ).
1H NMR (250 MHz, CDCl3): δ 6.65-6.77 (3H, m), 5.93 (2H,
s), 4.92 (1H, s), 4.86 (1H,s), 3.50-3.65 (2H, m), 3.33 (1H, t, J
) 7.5), 2.09 (1H, dq, J ) 7, 14), 1.83-1.98 (1H, m), 1.60 (3H,
s). 13C NMR (62 MHz, CDCl3): δ 147.86, 147.56, 145.99,
136.92, 120.85, 110.28, 107.96 (2), 100.79, 61.13, 48.59, 35.93,
21.00. IR (film): ν 3374, 2967, 2890, 1645, 1611, 1487, 1248,
1044. MS m/ z (rel intensity): 220 (M+, 100), 179 (62), 175
(62), 159 (27), 149 (51), 145 (98), 135 (64), 131 (47), 117 (52).
3-(3-Hyd r oxyp h en yl)-4-m eth oxy-4-m eth ylp en ta n -1-ol
(8d ). 1H NMR (250 MHz, CD3COCD3): δ 8.20 (1H, s), 7.07
(1H, t, J ) 8), 6.78-6.81 (1H, m), 6.75 (1H, d, J ) 8), 6.65
(1H, ddd, J ) 8, 2.5, 1), 3.63 (1H, s), 3.20-3.48 (2H, m), 3.19
(3H, s), 2.82 (1H, dd, J ) 11.5, 1.5), 2.03-2.21 (1H, m), 1.81-
1.98 (1H, m), 1.05 (6H, s). 13C NMR (62 MHz, CD3COCD3): δ
157.71, 144.60, 129.38, 121.84, 117.45, 114.01, 77.20, 61.35,
51.52, 49.08, 33.27, 24.10, 22.76. IR (KBr): ν 3287, 3162, 2951,
1586, 1483, 1281, 1134, 1069. MS m/ z (rel intensity): 224
(M+, 10), 181 (10), 177 (18), 175 (27), 159 (16), 147 (27), 133
(45), 131 (47), 121 (79), 120 (73), 119 (47) 115 (30), 111 (24),
107 (100), 105 (32), 103 (44). HRMS m/ z calcd for C13H20O3:
224.1412, found 224.1422.
4-Eth yl-3-(3-h ydr oxyph en yl)-4-m eth oxyh exan -1-ol (8e).
1H NMR (250 MHz, CD3COCD3): δ 7.06 (1H, t, J ) 8), 6.83
(1H, t, J ) 2.5), 6.78 (1H, dt, J ) 8, 2.5), 6.68 (1H, ddd, J ) 1,
2.5, 8), 3.30-3.35 (2H, m), 3.22 (3H, s), 3.10 (1H, dd, J ) 2.5,
12), 2.93 (1H, dd, J ) 2.5, 12), 2.06-2.20 (1H, m), 1.90 (1H,
dddd, J ) 4, 6.5, 12, 13), 1.40-1.75 (4H, m), 0.83 (3H, t, J )
7.5), 0.78 (3H, t, J ) 7.5). 13C NMR (62 MHz, CD3COCD3): δ
157.81, 144.66, 129.35, 122.21, 117.80, 113.95, 80.48, 61.26,
49.71, 48.96, 34.09, 27.42, 27.29, 9.07, 8.86. IR (film): ν 3349,
2946, 2886, 1587, 1455, 1258, 1051. MS m/ z (rel intensity):
252 (M+, 10), 222 (35), 220 (100), 191 (67), 175 (76), 173 (55),
161 (40), 147 (82), 145 (54), 133 (90), 121 (76), 107 (92). HRMS
m/ z calcd for C15H24O3: 252.1725, found 252.1713.
4-Meth oxy-3-(3-m eth oxyp h en yl)-4-m eth ylp en ta n -1-ol
(8h ). 1H NMR (250 MHz, CDCl3): δ 7.17 (1H, t, J ) 7), 6.71-
6.85 (3H, m), 3.78 (3H, s), 3.49 (1H, ddd, J ) 5, 7, 11.5), 3.36
(1H, ddd, J ) 6, 8, 11.5), 3.22 (3H, s), 2.82 (1H, dd, J ) 4,
10.5), 2.33 (1H, s), 2.15 (1H, dddd, J ) 4, 7, 8, 13.5), 1.92 (1H,
dddd, J ) 5, 6, 10.5, 13.5), 1.11 (3H, s), 1.05 (3H, s). 13C NMR
(62 MHz, CDCl3): δ 159.15, 143.46, 128.65, 122.05, 115.66,
111.25, 76.87, 61.38, 54.96, 51.39, 48.89, 32.58, 23.75, 21.81.
IR (film): ν 3387, 2942, 2834, 1601, 1487, 1256, 1049. MS
m/ z (rel intensity): 238 (M+, 35), 221 (72), 207 (100), 189 (75),
175 (32), 166 (31), 145 (34), 135 (90), 121 (42), 115 (47), 105
(50). HRMS m/ z calcd for C14H22O3: 238.1569, found 238.1552.
3-(Ben zo[1,3]d ioxol-5-yl)-4-m eth oxy-4-m eth ylp en ta n -
1-ol (8k ). 1H NMR (250 MHz, CDCl3): δ 6.77 (1H, d, J ) 1.5),
6.71 (1H, d, J ) 8), 6.66 (1H, dd, J ) 1.5, 8), 5.91 (2H, s), 3.52
(1H, ddd, J ) 5, 6.5, 10.5), 3.38 (1H, ddd, J ) 6, 8.5, 10.5),
3.22 (3H, s), 2.76 (1H, dd, J ) 4, 11), 2.14 (1H, dddd, J ) 4,
6.5, 8.5, 14), 1.96 (1H, s), 1.87 (1H, dddd, J ) 5, 6, 11, 14),
1.08 (3H, s), 1.06 (3H, s). 13C NMR (62 MHz, CDCl3): δ 147.28,
146.02, 135.64, 122.80, 109.50, 107.67, 100.76, 77.00, 61.57,
51.33, 49.05, 32.80, 23.78, 21.86. IR (film): ν 3399, 2973, 2888,
2830, 1611, 1487, 1244, 1040. MS m/ z (rel intensity): 252
(M+, 94), 205 (17), 203 (17), 180 (86), 176 (20), 173 (19), 165
(47), 161 (18), 149 (67), 148 (97), 147 (91), 135 (100), 118 (45),
103 (34). HRMS m/ z calcd for C14H22O4: 252.1362, found
252.1380.
3-(2,2-Dim eth yltetr a h yd r ofu r a n -3-yl)p h en ol (6d ). 1H
NMR (250 MHz, CD3COCD3): δ 7.12 (1H, t, J ) 8), 6.68-
6.80 (3H, m), 3.96 (1H, dt, J ) 4, 8.5), 3.83 (1H, dd, J ) 7.5,
8.5), 3.00 (1H, t, J ) 4), 2.17-2.43 (2H, m), 1.26 (3H, s), 0.80
(3H, s). 13C NMR (62 MHz, CD3COCD3): δ 158.07, 143.27,
129.81, 120.29, 116.07, 114.26, 82.79, 55.07, 32.30, 28.17,
23.89. IR (KBr): ν 2973, 2886, 1618, 1588, 1285, 1136, 1024.
MS m/ z (rel intensity): 192 (M+, 23), 177 (23), 161 (17), 149
(20), 147 (27), 135 (70), 134 (98), 133 (100), 121 (32), 119 (67),
117 (79), 116 (40), 115 (41), 111 (27), 107 (87), 105 (74), 103
(32). HRMS m/ z calcd for C12H16O2: 192.1150, found 192.1135.
3-(2,2-Dieth yltetr ah ydr ofu r an -3-yl)ph en ol (6e). 1H NMR
(250 MHz, CD3COCD3): δ 7.12 (1H, dd, J ) 7.5, 9.5), 6.68-
6.78 (3H, m), 4.08 (1H, dt, J ) 4.5, 8.5), 3.92 (1H, q, J ) 8.5),
3.20 (1H, t, J ) 8), 2.20-2.43 (2H, m), 1.72 (1H, dq, J ) 14.5,
7.5), 1.56 (1H, dq, J ) 14.5, 7.5), 1.41 (1H, dq, J ) 14.5, 7.5),
1.10 (1H, dq, J ) 14.5, 7.5), 0.96 (3H, t, J ) 7.5), 0.67 (3H, t,
J ) 7.5). 13C NMR (62 MHz, CD3COCD3): δ 155.99, 142.87,
129.12, 120.66, 115.28, 113.51, 87.77, 65.29, 50.21, 32.41,
27.66, 26.62, 7.98, 7.90. IR (film): ν 3299, 2969, 2880, 1599,
1462, 1151, 1044. MS m/ z (rel intensity): 220 (M+, 6), 191
(10), 134 (100), 133 (41), 124 (30), 117 (12), 107 (15). HRMS
m/ z calcd for C14H20O2: 220.1463, found 220.1461.
2,2-Dim eth yl-3-(3-m eth oxyph en yl)tetr ah ydr ofu r an (6h ).
1H NMR (250 MHz, CDCl3): δ 7.22 (1H, dd, J ) 9, 7.5), 6.75-
6.86 (3H, m), 4.05 (1H, dt, J ) 4, 8), 3.93 (1H, q, J ) 8), 3.80
(3H, s), 3.04 (1H, dd, J ) 8, 9.5), 2.22-2.45 (2H, m), 1.30 (3H,
s), 0.86 (3H, s). 13C NMR (62 MHz, CDCl3): δ 159.45, 142.09,
129.07, 120.73, 114.43, 111.45, 82.55, 64.98, 55.16, 54.40,
31.67, 27.79, 23.41. IR (film): ν 2971, 2880, 1601, 1493, 1157,
1046. MS m/ z (rel intensity): 206 (M+, 25), 191 (9), 161 (10),
149 (27), 148 (100), 147 (52), 133 (35), 121 (21), 117 (65), 105
(74). HRMS m/ z calcd for C13H18O2: 206.1307, found 206.1305.
3-(Ben zo[1,3]d ioxol-5-yl)-2,2-d im et h ylt et r a h yd r ofu -
r a n (6k ). 1H NMR (250 MHz, CDCl3): δ 6.62-6.78 (3H, m),
5.93 (2H, s), 3.97-4.08 (1H, m), 3.91 (1H, q, J ) 8), 2.98 (1H,
t, J ) 9), 2.20-2.34 (2H, m), 1.30 (3H, s), 0.85 (3H, s). 13C
NMR (62 MHz, CDCl3): δ 147.46, 146.16, 134.22, 121.21,
108.39, 107.84, 100.80, 82.35, 64.74, 54.05, 31.85, 27.57, 23.25.
IR (film): ν 2971, 2886, 1505, 1238, 1042. MS m/ z (rel
intensity): 220 (M+, 28), 162 (95), 138 (100), 132 (32), 130 (29),
104 (39). HRMS m/ z calcd for C13H16O3: 220.1099, found
220.1093.
3-(3-Hyd r oxyp h en yl)-4-m eth ylp en t-4-en -1-ol (7d ). 1H
NMR (250 MHz, CD3COCD3): δ 8.15 (1H, s), 7.10 (1H, t, J )
8), 6.64-6.75 (3H, m), 4.92 (1H, s), 4.80 (1H,s), 3.44-3.57 (2H,
m), 3.40 (2H, t, J ) 7.5), 1.80-2.12 (2H, m), 1.55 (3H, s). 13C
NMR (62 MHz, CD3COCD3): δ 158.27, 148.91, 146.00, 129.94,
119.96, 115.64, 114.04, 110.47, 60.64, 49.36, 36.98, 21.38. IR
(film): ν 3324, 3085, 2946, 1590, 1455, 1265, 1042. MS m/ z
(rel intensity): 192 (M+, 87), 161 (62), 159 (46), 148 (66), 147
(100), 145 (36), 133 (54), 131 (41), 121 (37), 115 (28), 107 (67),
103 (26). HRMS m/ z calcd for C12H16O2: 192.1150, found
192.1126.
4-Eth yl-3-(3-h ydr oxyph en yl)h ex-4-en -1-ol (7e). 1H NMR
(250 MHz, CD3COCD3): δ 8.15 (1H, s, broad), 7.0-7.12 (1H,
m), 6.60-6.76 (3H, m), 5.41 (1H, q, J ) 7, cis isomer), 5.32
(1H, tq, J ) 1.5, 7, trans isomer), 4.15 (1H, dd, J ) 6.5, 9),
3.35-3.64 (3H, m), 3.1 (1H, s, broad), 1.66-2.16 (4H, m), 1.79
(3H, dt, J ) 7, 1.5, trans isomer), 1.63 (3H, d, J ) 7, cis isomer),
0.84 (3H, t, J ) 7.5, trans isomer), 0.82 (3H, t, J ) 7.5, cis
isomer). 13C NMR (62 MHz, CD3COCD3): δ 158.16, 146.94
(cis isomer), 146.47 (trans isomer), 145.25, 129.94, 119.78,
120.24 (cis isomer), 119.76 (trans isomer), 118.39, 115.85 (cis
isomer), 115.73 (trans isomer), 60.82, 48.35, 41.57, 37.66 (cis
isomer), 35.03 (trans isomer). IR (film): ν 3337, 2963, 2876,
1694, 1590, 1455, 1030. MS m/ z (rel intensity): 220 (M+, 100),
191 (9), 189 (8), 187 (13), 176 (26), 175 (46), 173 (25), 161 (17),
159 (18), 147 (40), 145 (21), 133 (45), 120 (62), 119 (74), 118
(65), 117 (75), 110 (20), 107 (32). HRMS m/ z calcd for
C14H20O2: 220.1463, found 220.1466.
3-(Ben zo[1,3]d ioxol-5-yl)-4-m eth ylp en ta n -1-ol (9k ). 1H
NMR (250 MHz, CDCl3): δ 0.88 (3H, d, J ) 6.5), 0.65 (3H, d,
J ) 7). 13C NMR (62 MHz, CDCl3): δ 147.53, 137.72, 121.42,
108.18, 100.71, 61.49, 49.30, 36.05, 33.59, 20.88, 20.62.
3-(3,4-Dim eth oxyp h en yl)bu ta n -1-ol (9l). 1H NMR (250
MHz, CDCl3): δ 6.71-6.85 (3H, m), 3.87 (3H, s), 3.85 (3H, s),
3-(3-Meth oxyp h en yl)-4-m eth ylp en t-4-en -1-ol (7h ). 1H
NMR (250 MHz, CDCl3): δ 7.19 (1H, t, J ) 7.5), 6.63-6.85

6960 J . Org. Chem., Vol. 62, No. 20, 1997
Hoffmann and Pete
3.50-3.62 (1H, m), 2.83 (1H, sex, J ) 6.5), 1.82 (2H, q, J )
6.5), 1.65 (1H, s, broad), 1.26 (3H, d, J ) 6.5). 13C NMR (62
MHz, CDCl3): δ 149.00, 147.37, 139.61, 118.70, 111.43, 110.40,
61.16, 55.89, 55.84, 41.09, 36.09, 22.47. IR (film): ν 3426,
2961, 2837, 1593, 1520, 1264, 1144, 1032. MS m/ z (rel
intensity): 210 (M+, 62), 179 (10), 166 (31), 165 (100), 151 (30),
145 (16), 135 (18), 121 (21), 105 (10), 103 (11). HRMS m/ z
calcd for C12H18O3: 210.1256, found 210.1257.
F lu or escen ce Stu d ies. The spectra were acquired in a 1
cm path length cuvette using a Perkin-Elmer LS 50 lumines-
cence spectrometer. λex ) 274 nm, λem ) 306 nm. Methanolic
solutions of 30.8 mmol/L of 1f and 27.8 mmol/L of 1,3-
dimethoxybenzene were messured in absence and presence of
H2SO4 (103 mmol/L).
petroleum ether/ethyl acetate 1/1). The samples were analyzed
by GC: HP 6890 series (Hewlett-Packard); column, HP-1
(cross-linked methylsiloxane: 30 m × 0.25 mm × 0.25 mm
film thickness).
Ack n ow led gm en t. We are gratefull to Dr. Karola
Scha¨fer and to Prof. Dr. Hartwig Ho¨cker (Deutsches
Wollforschungsinstitut, Aachen, Germany) for having
given us the opportunity to record fluorescence spectra.
Our thanks are also directed to Dr. Karen Ple´ (UPRESA
CNRS, Universite´ de Reims) for the language correc-
tions.
Qu a n tifica tion of th e In flu en ce of Acid on th e Ra te
of Con ver sion . Methanolic solutions (16 mL) of 0.5 mmol of
1f and different concentrations of H2SO4 were irradiated at λ
) 254 nm (Rayonet, T ) 35 °C). After 2.5 h, the reaction had
stopped. A methanolic solution containing 3.3 mg of 1,3-
dimethoxybenzene was added (internal standart). The solu-
Su p p or tin g In for m a tion Ava ila ble: 13C NMR sprecta of
all described compounds and mixtures of compounds (41
pages). This material is contained in libraries on microfiche,
immediately follows this article in the microfilm version of the
journal, and can be ordered from the ACS; see any current
masthead page for ordering information.
tions were then treated with NaHCO3 and evaporated.
A
mixture of ethyl acetate and petroleum ether (1/1) was added.
The resulting mixture was filtred with silica gel (eluent,
J O970554T