Chemistry Letters 2001
449
Hz), 6.75 (s, 1H), 5.5–6.7 (br s, 1H). 13C NMR (100 MHz, acetone-
d6): δ 151.8, 134.7, 134.1, 133.8, 133.6, 133.4, 130.1, 128.6, 127.2,
1
26.6, 126.43, 126.37, 123.8, 122.8, 120.6, 120.5, 93.3, 70.2.
Naphthopyranylhemiacetal (2): colorless prisms. mp 198.5–200.0
°
C (dec). Anal. Calcd for C18H10Cl O : C, 51.96; H, 2.42; Cl,
4 3
3
4.08; O, 11.53%. Found: C, 52.35, H, 2.78, Cl, 33.72%. FAB-MS
+
(
m-NBA as a matrix) m/z 397 (M +H). HRMS (EI): Calcd for
1
C H Cl O (M–H O) 395.9278. Found 395.9267. H NMR (400
1
8
8
4
2
2
MHz, acetone-d ): δ 7.95 (d, 1H, J = 8.1 Hz), 7.85 (d, 1H, J = 8.1
6
Hz), 7.73 (d, 1H, J = 7.8 Hz), 7.63 (dd, 1H, J = 8.1, 7.8 Hz), 7.43 (s,
1
1
1
1
H), 7.41 (dd, 1H, J = 8.1, 7.8 Hz), 6.87 (d, 1H, J = 7.8 Hz), 6.37 (s,
H), 5.3–6.8 (br s, 1H). 13C NMR (100 MHz, acetone-d ): δ 152.2,
6
34.7, 134.1, 133.4, 132.7, 130.5, 129.5, 129.2, 127.5, 126.8, 126.7,
26.3, 124.6, 123.0, 121.1, 120.7, 94.9, 71.5.
6
A colorless single crystal with dimension of 0.20 × 0.30 × 0.20 mm
was collected on a Rigaku AFC5R diffractometer using graphite
monochromatic Cu Kα radiation (λ = 1.54178 Å) and 12 kW rotat-
ing anode generator at 23 °C. The structure was elucidated by a
direct method using TEXSAN. 13 Crystal data for 2·C H OH
2
5
(
C H Cl O ): MW = 430.07, monoclinic, space group C2/c (#15),
20 16 4 4
a = 12.799 (3) Å, b = 11.909 (3) Å, c = 27.843 (4) Å, β = 99.67 (2)°,
3
–3
–1
V = 4183 (1) Å , Z = 8, Dcalc/g cm = 1.366, µ = 53.17 cm , 3937
reflections measured, 3586 unique (Rint = 0.025), RI (I > 3σ), =
0
.075, R = 0.136, Rw = 0.228.
7
8
R. M. Wilson, S. W. Wunderly, T. F. Walsh, A. K. Musser, R.
Outcalt, F. Geiser, S. K. Gee, W. Brabender, L. Yerino, Jr., T. T.
Conrad, and G. A. Tharp., J. Am. Chem. Soc., 104, 4429 (1982).
trans-1-Methoxy-3-(2,3,5,6-tetrachloro-4-hydroxyphenyl)-1H,3H-
naphtho[1,8-cd]pyran (7a): colorless prisms. mp 182.0–183.0 °C.
Anal. Calcd for C19H12Cl O : C, 53.06; H, 2.81; Cl, 32.97; O,
labile oxetanes produced on irradiation of styrene and 1,4-ben-
7
zoquinone gives dihydrobenzofuran.
4
3
Furthermore, on treatment with primary alcohols such as
methanol and ethanol but not with tert-butyl alcohol, both 1 and
were quantitatively converted into an identical naphthopy-
ranylacetal (7) carrying with trans configuration between the
11.16%. Found: C, 52.88, H, 2.68, Cl, 32.75%. FAB-MS (m-NBA):
+
1
m/z 428 (M +1). H NMR (400 MHz, CDCl ): δ 7.89 (dd, 1H, J =
3
8
7
.1, 1.2 Hz), 7.79 (d, 1H, J = 8.4 Hz), 7.55 (dd, 1H, J = 8.1, 7.2 Hz),
.45 (dd, 1H, J = 7.2, 1.2 Hz), 7.36 (dd, 1H, J = 8.4, 7.2 Hz), 7.24
2
(s, 1H), 6.78 (dt, 1H, J = 7.2, 1.2 Hz), 6.25 (br s, 1H), 5.90 (s, 1H),
13
alkoxy group and the aryl group on the naphthopyran ring
3.70 (s, 3H). C NMR (100 MHz, CD OD): δ 153.1, 125.3, 134.7,
3
8
134.1, 133.7, 131.6, 129.5, 129.4, 127.7, 126.91, 126.86, 126.8,
(
Scheme 2). The structure of 7a (R = CH ) was unambiguously
3
1
24.7, 121.0, 100.8, 71.0, 55.8. trans-1-Ethoxy-3-(2,3,5,6-tetra-
established by X-ray crystallography of a single crystal com-
posed by 7a and dichloromethane as a crystallization solvent in
a ratio of 1:1.9
In conclusion, direct excitation of ACN and TCBQ with >
20 nm light in solution gives two anomeric naphthopyranyl-
chloro-4-hydroxyphenyl)-1H,3H-naphtho[1,8-cd]pyran (7b): color-
less prisms. mp 178.0–179.0 °C. Anal. Calcd for C H Cl O : C,
2
0
14
4
3
54.08; H, 3.18; Cl, 31.93; O, 10.80%. Found: C, 53.75, H, 3.12, Cl,
1
3
1
7
2.35%. EI-MS: m/z 442. H NMR (400 MHz, CDCl ): δ 7.88 (dd,
3
H, J = 8.2, 1.2 Hz), 7.78 (d, 1H, J = 8.3 Hz), 7.55 (dd, 1H, J = 8.2,
.2 Hz), 7.45 (dd, 1H, J = 7.2, 1.2 Hz), 7.36 (dd, 1H, J = 8.3, 7.2
4
hemiacetals between ACN and TCBQ. These hemiacetals
facilely anomerize each other like sugars in aqueous solutions,
and both of these are converted solely into an identical naph-
thopyranylacetal in primary alcohol. To the best of our knowl-
edge, formation of products with naphthopyran skeleton is the
first finding in photochemical reactions of benzoquinones with
unsaturated compounds, which are known to give cyclobutanes,
Hz), 7.27 (s, 1H), 6.78 (dt, 1H, J = 7.2, 1.2 Hz), 6.26 (br s, 1H), 6.02
(s, 1H), 4.12 (dq, 1H, J = 10.0, 7.2 Hz), 3.84 (dq, 1H, J = 10.0, 7.2
1
3
Hz), 1.36 (t, 3H, J = 7.2 Hz).
C NMR (100 MHz, CDCl ): δ
3
1
1
49.4, 134.2, 133.7, 132.7, 132.1, 130.3, 129.3, 128.4, 126.6, 125.8,
25.6, 125.4, 123.3, 121.2, 119.9, 118.8, 98.3, 98.1.
9
1
A colorless single prism with dimension of 0.30 × 0.30 × 0.20 mm
was used. Crystal data for 7a·CH Cl (C20H13Cl O ): MW =
2
2
6
3
−
5
14.04, triclinic, space group, P1 (#2); Lattice parameters, a =
10,11
10.789 (2) Å, b = 11.964 (2) Å, c = 8.388 (1) Å, α = 93.52 (2)°, β =
oxetanes or ethers.
3
1
03.84 (1)°, γ = 85.22 (2)°, V = 1046.7 (6) Å , Z value, 2; Dcalc/g
–
3
–1
cm , 1.631, µ = 78.61 cm , 3893 reflections measured, 3683
unique (Rint = 0.076), RI (I > 3σ), = 0.075, R, 0.070; Rw, 0.080.
0 a) N. J. Bunce, in “The Chemistry of Quinoid Compounds, Part 1,”
ed. by S. Patai, Wiley & Sons, New York (1974), pp. 465–538, and
references cited therein. b) K. Maruyama and A. Osuka, in “The
Chemistry of Quinoid Compounds, Part 2;” ed. by S. Patai and Z.
Rappoport, Wiley & Sons, New York (1988), pp. 759–878, and ref-
erences cited therein. c) D. Creed, in “CRC Handbook of Organic
Photochemistry and Photobiology,” ed. by W.M. Horspool and P-S.
Song, CRC Press, Boca Raton, Florida (1995), pp. 737–747. d) K.
Maruyama and Y. Kubo, “CRC Handbook of Organic
Photochemistry and Photobiology,” pp. 748–756.
References and Notes
1
2
3
N. Haga, H. Takayanagi, and K. Tokumaru, J. Org. Chem., 62, 5372
1998).
N. Haga, H. Takayanagi, and K. Tokumaru, Chem. Commun., 1998,
093.
At 432 nm, both ACN and TCBQ have comparable molar absorption
coefficients. Therefore, under > 420 nm irradiation, both of ACN
and TCBQ will be nearly equally excited.
(
2
4
5
Light from a 400 W high-pressure mercury lamp was passed through
1
1
a color-glass filter.
Preparative photolysis and determination of quantum yield were
done according to the previous method.1
pyranylhemiacetal (1): colorless fine prisms. mp 202.5–203.0 °C
dec). Anal. Calcd for C H Cl O : C, 51.96; H, 2.42; Cl, 34.08;
,12
Naphtho-
1
1 a) G. Jones, II, in “Organic Photochemistry,” ed. by S. Padwa,
Marcel Dekker, New York (1981), vol. 5, pp. 1–122. b) A. G.
Griesbeck, in “CRD Handbook of Organic Photochemistry and
Photobiology,” ed. by W. M. Horspool and P-S. Song, CRC Press,
Boca Raton, Florida (1995), pp. 522–535.
(
18
10
4
3
O, 11.53%. Found: C, 52.32, H, 2.80, Cl, 33.70%. FAB-MS (m-
+
nitrobenzylamine (m-NBA) as a matrix) m/z 397 (M +H). HRMS
(
EI): Calcd for C H Cl O (M–H O) 395.9278. Found 395.9286.
18 8 4 2 2
12 N. Haga, H. Takayanagi, and K. Tokumaru, J. Org. Chem., 62, 3734
1
H NMR (400 MHz, acetone-d ): δ 7.93 (d, 1H, J = 8.2 Hz), 7.85 (d,
6
(1997).
1H, J = 8.0 Hz), 7.57 (dd, 1H, J = 8.2, 8.0 Hz), 7.45 (d, 1H, J = 8.2
1
3 TEXSAN: Structure Analysis Package, Molecular Structure
Corporation (1985 and 1999).
Hz), 7.41 (s, 1H), 7.40 (dd, 1H, J = 8.2, 8.0 Hz), 6.87 (d, 1H, J = 8.0