K. Sriraghavan, V. T. Ramakrishnan / Tetrahedron 59 (2003) 1791–1796
1795
C17H14O2 requires C, 81.58; H, 5.63%]; nmax (KBr) 3400,
3020, 2980, 1630, 1590, 1500, 1420, 970, 860 cm21; dH
(90 MHz, CDCl3) 12.5 (1H, s, Ar-OH), 7.7 (4H, m, Ar-H),
7.0 (3H, m, Ar-H), 5.8 (2H, m, H6 and H7) 3.3 (4H, bs, 5 and
8-CH2); m/z (EI) 250 (Mþ, 100), 171 (26), 145 (18), 127
(12), 115 (35), 105 (94), 91 (9), 77 (82).
254 nm, for 24 h furnished the compounds 3g, 4g and
5,8-dihydro-1-naphthol 1 (30%).
1.9.1. 2-(1-Naphthoyl)-5,8-dihydro-1-naphthol (3g).
Yield: 0.19 g (30%); mp 130–1328C; [Found: C, 84.42;
H, 5.30. C21H16O2 requires C, 83.98; H, 5.37%]; nmax (KBr)
3420, 3200, 2990, 1630, 1620, 1590 cm21; dH (300 MHz,
CDCl3) 12.87 (1H, s, D2O exchanged, Ar-OH), 7.98 (3H, m,
Ar-H), 7.51 (4H, m, Ar-H), 7.08 (1H, bs, Ar-H), 6.49 (1H,
bs, Ar-H4), 5.9 (1H, bs, H6), 5.85 (1H, bs, H7), 3.40 (4H, bs,
5 and 8CH2); dc (75 MHz, CDCl3) 203.3, 161.5, 144.1,
136.0, 133.5, 130.8, 130.6, 130.4, 128.4, 127.1, 126.5,
126.1, 125.5, 125.4, 124.5, 124.4, 123.8, 122.9, 118.9,
117.6, 30.3, 23.6; m/z (EI) 300 (Mþ, 100), 283 (5), 281 (9),
173 (18), 172 (50), 171 (36), 155 (35), 144 (15), 128 (27),
127 (49), 77 (11).
1.7. Irradiation of 5,8-dihydro-1-naphthyl 2-methyl-
benzoate (2e)
Photolysis of the ester 2e (1 g, 3.8 mmol) in benzene
(150 mL) at 254 nm, for 24 h furnished, the ortho
rearranged product (3e) along with 5,8-dihydro-1-naphthol
1 (30%).
1.7.1. 2-(2-Methylbenzoyl-5,8-dihydro-1-naphthol (3e).
Yield: 0.35 g (35%); mp 78–808C; [Found: C, 81.20; H,
5.98. C18H16O2 requires C, 81.79; H, 6.10%]; nmax (KBr)
3400, 3025, 2890, 1630, 1590, 880, 870 cm21. dH
(300 MHz, CDCl3) 12.8 (1H, s, Ar-OH), 8.53 (1H, d, J¼
7.5 Hz, Ar-H3), 7.65 (1H, m, Ar-H), 7.30 (2H, m, Ar-H),
7.10–7.75 (4H, m), 6.56 (1H, d, J¼7.5 Hz, Ar-H4), 5.90
(2H, m, H6 and H7), 3.40 (4H, bs, 5 and 8-CH2), 2.31 (3H, s,
Ar-CH3); dc (75 MHz, CDCl3) 204.0, 161.4, 143.9, 138.1,
135.2, 130.7, 129.6, 129.8, 127.3, 125.9, 118.9, 117.0,
113.4, 30.21, 23.6, 19.5; m/z (EI) 264 (Mþ, 65), 263 (12),
249 (69), 247 (65), 245 (21), 223 (15), 173 (13), 172 (14),
171 (35), 170 (53), 119 (51), 115 (48), 114 (18), 91 (100), 90
(13), 77 (10), 65 (57), 51 (22).
1.9.2. 4-(1-Naphthoyl)-5,8-dihydro-1-naphthol (4g). Yield:
0.125 g (20%); mp 206–2088C; [Found: C, 84.08; H, 5.40.
C21H16O2 requires C, 83.98; H, 5.37%]; nmax (KBr) 3400,
3000, 2920, 2850, 1620, 1420, 1330 cm21; dH (300 MHz,
CDCl3) 10.40 (1H, s, Ar-OH), 8.02 (3H, m, Ar-H), 7.50
(4H, m, Ar-H), 7.06 (1H, m, Ar-H), 6.66 (1H, m, Ar-H), 5.9
(2H, m, H6 and H7), 3.72 (2H, m, 5-CH2), 3.25 (2H, m,
8-CH2); dc (75 MHz, DMSO-d6) 158.49, 138.4, 137.0,
133.2, 132.5, 130.6, 130.1, 128.4, 128.2, 128.1, 127.3,
127.1, 126.3, 125.32, 124.8, 124.2, 123.0, 122.2, 111.1,
28.3, 23.9; m/z (EI) 300 (Mþ, 100), 299 (13), 283 (13), 281
(13), 172 (15), 171 (91), 156 (11), 155 (77), 145 (16), 144
(10), 143 (13), 128 (20), 127 (82), 126 (37), 77 (17), 51 (16).
1.8. Irradiation of 5,8-dihydro-1-naphthyl 2-chloro-
benzoate (2f)
1.10. Irradiation of 5,8-dihydro-1-naphthyl cinnamate
(2h)
Photolysis of ester 2f (1 g, 3.5 mmol) in MeOH at 254 nm,
for 24 h furnished the products 3f, 4f and 5,8-dihydro-1-
naphthol 1 (40%).
Photolysis of the ester 2h (1 g, 3.62 mmol) in MeOH at
254 nm, for 24 h furnished only the ortho rearranged
product 3h in low yield along with 5,8-dihydro-1-naphthol
1 (40%).
1.8.1. 2-Chlorobenzoyl-5,8-dihydro-1-naphthol (3f).
Yield: 0.25 g (25%); mp 112–1148C; [Found: C, 72.08;
H, 4.70. C17H13ClO2 requires C, 71.71; H, 4.60%]; nmax
(KBr) 3420, 3020, 2980, 1620, 1600, 1520, 1480 cm21; dH
(300 MHz, CDCl3) 12.2 (1H, s, Ar-OH), 7.55 (4H, m,
Ar-H), 7.0 (1H, d, J¼9 Hz, H3), 6.7 (1H, d, J¼9 Hz, H4), 5.9
(2H, m, H6 and H7), 3.4 (2H, bs, 8-CH2), 3.2 (2H, bs,
5-CH2); m/z (EI) 286 (Mþ2, 32), 284 (Mþ, 88), 283 (15),
282 (15), 250 (15), 249 (82), 247 (56), 173 (33), 171 (23),
145 (35), 141 (33), 139 (100), 115 (39), 111 (39), 91 (10).
1.10.1. 2-Cinnamoyl-5,8-dihydro-1-naphthol (3h). Yield:
0.15 g (15%); mp 116–1188C; [Found: C, 82.08; H, 5.50.
C19H16O2 requires C, 82.58; H, 5.83 %]; nmax (KBr) 3040,
1630, 1570, 1580, 1420, 1350, 1280, 1120, 760 cm21; dH
(90 MHz, CDCl3) 13.0 (1H, s, D2O exchanged, Ar-OH), 7.5
(5H, m, Ar-H), 7.3 (3H, m, Ar-H), 6.6 (1H, d, J¼9 Hz, H4),
5.80 (2H, m, H6 and H7), 3.3 (4H, bs, 5 and 8-CH2); m/z (EI)
276 (Mþ, 63), 275 (33), 257 (8), 199 (36), 197 (15), 173
(14), 172 (34), 171 (51), 170 (100), 144 (22), 131 (43), 115
(37), 103 (36), 91 (16).
1.8.2. 4-(2-Chlorobenzoyl)-5,8-dihydro-1-naphthol (4f).
Yield: 0.1 g (10%); mp 210–2128C; [Found: C, 71.36; H,
4.52. C17H13ClO2 requires C, 71.71; H, 4.60%]; nmax (KBr)
3400, 3020, 2990, 1640, 1600, 1580, 1420 cm21; dH
(300 MHz, DMSO-d6) 10.6 (1H, s, Ar-OH), 7.5 (4H, m,
Ar-H), 7.05 (1H, d, J¼9.0 Hz, H3), 6.7 (1H, d, J¼9.0 Hz,
H2), 5.9 (2H, m, H6 and H7), 3.25 (2H, m, 8-CH2), 3.2 (2H,
m, 5-CH2); m/z (EI) 286 (Mþ2, 16), 284 (Mþ, 24), 283
(24), 282 (2), 251 (53), 249 (48), 231 (25), 175 (6), 145 (32),
141 (33) 139 (100), 127 (14), 115 (25), 111 (32), 91 (7.7).
1.11. Reaction of 5,8-dihydro-1-naphthyl acetate (2a)
with AlCl3 in benzene
Anhydrous aluminium chloride (4.2 g, 32 mmol) was added
in portion to the solution of the ester 2a (1 g, 5.3 mmol) in
dry benzene (30 mL) at room temperature. Then the
reaction mixture was refluxed on a water bath. After the
disappearance of the starting material monitered by tlc,
the reaction mixture was cooled and ice water (50 mL)
added. The organic layer was separated and washed several
times with dil. HCl and water and dried over magnesium
sulphate. After distilling off the solvent, the residue was
chromatographed over a silica gel column and eluted with
1.9. Irradiation of 5,8-dihydro-1-naphthyl a-naphthoate
(2g)
Photolysis of 2g (0.64 g, 2.1 mmol) in benzene (150 mL) at