4142 J . Org. Chem., Vol. 63, No. 12, 1998
Notes
(250 mL) of methylmagnesium iodide in dry diethyl ether, and
the mixture was refluxed for 4 h. The cold solution was then
hydrolyzed by the addition of saturated aqueous ammonium
chloride (400 mL). The phases were separated, the aqueous
phase was extracted twice with diethyl ether (200 mL), and the
combined organic phases were dried (MgSO4) and evaporated
to dryness under reduced pressure. The residue was redissolved
in dichloromethane and stirred vigorously for 30 min with 10%
hydrochloric acid. Usual workup and bulb to bulb distillation
afforded the 4-methyl-1,2-dihydronaphthalenes (ca. 90%).
A solution of the olefins 12a -e (ca. 90 mmol) and N-
methylmorpholine N-oxide (14.9 g, 108 mmol) in acetone (100
mL) was then treated with a solution of osmium tetroxide in
tert-butyl alcohol (4.5 mL, 0.2 mmol/L), and the mixture was
stirred for 2 d. Sodium dithionite (9.5 g, 54 mmol) and Florisil
(4.5 g) were added, and the suspension was stirred for 1 h,
filtered, diluted with water (450 mL), and extracted twice with
dichloromethane (100 mL). The combined organic phases were
vigorously stirred with 6 N hydrochloric acid, and the organic
phase was separated, dried (MgSO4), evaporated to dryness
under reduced pressure, and distilled by bulb to bulb distillation
to yield the 2-tetralones 13b-e (ca. 75%).
The tetralones 13a -e (13a is commercially available) were
mixed with palladium on charcoal (10%, 2.5 g) and refluxed in
dry mesitylene (25 mL) under nitrogen for 3 h. The hot solution
was filtered and rinsed with hot mesitylene (120 mL). The bulk
part of the 2-naphthol crystallized from the cold mesitylene
solution. A second crop was obtained from chromatography of
the mother liquor on silica gel to yield ca. 50-70% (based on
the 1-tetralones) of the 2-naphthols 1a -e.
Gen er al P r ocedu r e II for th e Oxygen ation of th e 2-Naph -
th ols 1a -e to th e r-Ketols 2a -e. A solution of the 2-naph-
thols 1a -e (10 mmol) in dry dichloromethane (10 mL) was
treated with Zr(acac)4 (1 mmol) and powdered activated molec-
ular sieves (0.3 nm, 0.5 g), and the mixture was stirred for 30
min. A solution of tert-butyl hydroperoxide (TBHP) (22 mmol)
in dry dichloromethane (25 mL) was then added, and the
suspension was stirred for 12-15 h at 20 °C (TLC control).
Sulfuric acid (10 mL, 10%) was then added under stirring (30
min). The mixture was filtered, water (100 mL) was added, the
organic phase was separated, and the aqueous phase was
extracted twice with dichloromethane (100 mL). The combined
organic phases were dried (MgSO4) and evaporated to dryness
under reduced pressure, and the crude products were purified
by crystallization (yields 75-90%).
Gen er a l P r oced u r e III for th e Silyla tion of th e r-Ketols
2a -e to th e Silyl Eth er s 19a -e. A solution of the R-ketols
2a -e (10 mmol) in dry dichloromethane (50 mL) and pyridine
(0.85 mL, 11 mmol) was treated with trimethylsilyl chloride
(TMSCl) (1.6 mL, 12.5 mmol), and the mixture was stirred for
18 h at 20 °C. The solution was diluted by addition of n-pentane
(200 mL), the pyridinium hydrochloride was filtered off, and the
filtrate was evaporated to dryness under reduced pressure. The
crude silyl ethers 19a -e were purified by bulb to bulb distillation
(yield >95%).
Gen er a l P r oced u r e IV for th e Rea ction of th e r-Ketols
2a -e w ith Gr ign a r d Rea gen ts. The solution of the ca. 1 M
Grignard reagents were prepared from magnesium turnings (2.4
g, 0.1 mmol) and 2-bromopropane or 2-bromobutane (0.1 mmol)
in dry diethyl ether (10 mL) and dilution to 100 mL. A solution
of the ketols 2a -d (1 mmol) in dry diethyl ether (15 mL) was
then treated portionwise with the Grignard solution (2.5 mL)
and the mixtures were refluxed for 4 h. Alternatively, the
mixtures were stirred for 8 h at 20 °C. The mixtures were then
hydrolyzed by addition of aqueous ammonium chloride (10 mL),
the organic phase was separated, and the aqueous phase
extracted with diethyl ether (15 mL). The combined organic
phases were dried (MgSO4) and evaporated to dryness under
reduced pressure. The mixtures were separated by thin-layer
chromatography.
°C within 8 h and was then hydrolyzed by addition of saturated
aqueous ammonium chloride (10 mL). The organic phase was
separated, the aqueous phase extracted twice with diethyl ether,
dried (MgSO4), and evaporated to dryness under reduced pres-
sure. The residue was separated by column or preparative thin-
layer chromatography on silica gel.
7-Meth oxy-1,6-d im eth yln a p h th a len e-2-ol (1d ) was pre-
pared from 13d (19.0 g, 0.1 mol) according to the general
procedure I: yield 11.1 g (55%); mp 170 °C; IR (KBr) ν 3250,
1
3005, 2956, 2912, 2842, 1874, 1770, 1645, 1590 cm-1; H NMR
(200 MHz, CDCl3/CD3OD 1:0.01) δ 2.33 (s, 3 H, 1-CH3), 2.48 (s,
3 H, 6-CH3), 2.85 (s, 1 H, 2-OH), 3.95 (s, 3 H, OCH3), 6.87 (d, J
) 8.7 Hz, 1 H, 3-H), 7.06 (s, 1 H, 8-H), 7.45 (d, J ) 8.7 Hz, 1 H,
4-H), 7.47 (s, 1 H, 5-H); 13C NMR (50 MHz, CDCl3/CD3OD 1:0.01)
δ 14.91 (q, 1-CH3), 20.66 (q, 6-CH3), 59.42 (q, OCH3), 104.72 (d,
8-C), 118.81 (s, 1-C), 119.26 (d, 3-C), 128.29 (s, 6-C), 129.04 (s,
10-C), 130.13 (d, 5-C), 133.54 (d, 4-C), 138.23 (s, 9-C), 155.38 (s,
2-C), 161.48 (s, 7-C); MS (80 eV); m/z 202 (100) [M+], 187 (3),
171 (3), 159 (7). Anal. Calcd for C13H14O2: C, 77.20; H, 6.98.
Found: C, 77.42; H, 7.20.
1-H yd r oxy-7-m et h oxy-1,6-d im et h yl-1H -n a p h t h a len e-2-
on e (2d ) was prepared from 1d (2.0 g, 10 mmol) according to
the general procedure II: yield 1.9 g (89%), yellow crystals; mp
104 °C; IR (KBr) ν 3452, 2988, 2924, 2864, 2826, 2353, 2325,
1671 cm-1 1H NMR (200 MHz, CDCl3) δ 1.56 (s, 3 H, 1-CH3),
;
2.22 (s, 3 H, 6-CH3), 3.94 (s, 3 H, OCH3), 3.95 (s, 1 H, 1-OH),
6.06 (d, J ) 9.8 Hz, 1 H, 3-H), 7.07 (s, 1 H, 8-H), 7.21 (s, 1 H,
5-H), 7.38 (d, J ) 9.8 Hz, 1 H, 4-H); 13C NMR (50 MHz, CDCl3)
δ 16.20 (q, 6-CH3), 34.03 (q, 1-CH3), 56.09 (q, OCH3), 77.70 (s,
1-C), 107.76 (d, 8-C), 119.85 (d, 3-C), 121.19 (s, 6-C), 126.31 (s,
10-C), 132.27 (d, 5-C), 145.78 (s, 9-C), 146.47 (d, 4-C), 160.44 (s,
7-C), 206.05 (s, 2-C); MS (80 eV) m/z 217 (7) [M+ - H], 200 (17),
190 (3). Anal. Calcd for C13H14O3: C, 71.54; H, 6.47. Found:
C, 71.68; H, 6.64.
7-Meth oxy-1,6-d im eth yl-1-tr im eth ylsila n yloxy-1H-n a p h -
th a len e-2-on e (19d ) was prepared from 2d (2.2 g, 10 mmol)
according to the general procedure III: yield 2.8 g (98%), yellow
oil; bp 170-180 °C/0.7 Torr; IR (film) ν 3462, 2978, 2934, 2874,
2836, 2363, 2330, 1677 cm-1; 1H NMR (200 MHz, CDCl3) δ 0.09
(s, 9 H, OTMS), 1.54 (s, 3 H, 1-CH3), 2.24 (s, 3 H, 6-CH3), 3.92
(s, 3 H, OCH3), 6.03 (d, J 3,4 ) 9.8 Hz, 1 H, 3-H), 7.07 (s, 1 H,
5-H), 7.19 (s, 1 H, 8-H), 7.31 (d, J 3,4 ) 9.8 Hz, 1 H, 4-H); 13C
NMR (50 MHz, CDCl3) δ 2.14 (q, OTMS), 16.19 (q, 6-CH3), 34.20
(q, 1-CH3), 55.85 (q, OCH3), 80.61 (s, 1-C), 108.08 (d, 8-C), 121.45
(s, 6-C), 121.83 (d, 3-C), 126.23 (s, 10-C), 132.01 (d, 5-C), 145.01
(d, 4-C), 148.37 (s, 9-C), 160.18 (s, 7-C), 204.49 (s, 2-C); MS (80
eV) m/z 291 (3) [M+ + H], 275 (100), 260 (28), 231 (9), 201 (12),
173 (3), 141 (1), 129 (3), 115 (8), 103 (2). Anal. Calcd for
C16H22O3Si: C, 66.17; H, 7.64. Found: C, 64.86; H, 6.96.
7-Met h oxy-1,6-d im et h yl-4-(2-p r op yl)-n a p h t h a len e-2-ol
(23d ) was prepared from 19d (290 mg, 1.0 mmol) according to
the general procedure V: yield 161 mg (66%), colorless crystals;
mp 168 °C (ref8 mp 169-172 °C); 1H NMR (200 MHz, CDCl3) δ
1.40 (d, J ) 6.7 Hz, 6 H, CH(CH3)2), 2.42 (s, 3 H, 1-CH3), 2.52
(s, 3 H, 6-CH3), 3.70 (m, J ) 6.8 Hz, 1 H, CH(CH3)2), 4.01 (s, 3
H, OCH3), 4.81 (s, 1 H, 1-OH), 6.88 (s, 1 H, 3-H), 7.15 (s, 1 H,
8-H), 7.83 (s, 1 H, 5-H).
1-Hydr oxy-7-m eth oxy-1,6-dim eth yl-4-(2-pr opyl)-1H-n aph -
th a len e-2-on e (r a c-la cin ilen e
C m eth yl eth er , 3d ) was
prepared from 23d (244 mg, 10 mmol) according to the general
procedure II: yield 190 mg (73%), yellow crystals; mp 101-103
1
°C (lit.15 mp 100 °C); H NMR (200 MHz, CDCl3) δ 1.29 (d, J )
6.7 Hz, 3 H, CH(CH3)2), 1.31 (d, J ) 6.8 Hz, 3 H, CH(CH3)2),
1.56 (s, 3 H, 1-CH3), 2.27 (s, 3 H, 6-CH3), 3.25 (m, J ) 6.8 Hz, 1
H, CH(CH3)2), 3.95 (s, 3 H, OCH3), 3.96 (s, 1 H, 1-OH), 6.05 (s,
1 H, 3-H), 7.25 (s, 1 H, 8-H), 7.38 (s, 1 H, 5-H).
Su p p or tin g In for m a tion Ava ila ble: Detailed experi-
mental procedures and spectral data for compounds 1a -e, 2a -
e, 3a -e, 19a -e, 21a -c, 22a -c, and 23a -e (21 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.
Gen er a l P r oced u r e V for th e Rea ction of th e Silyl
Eth er s 19a -e w ith Cu p r a tes. A suspension of copper(I)
cyanide (358 mg, 4.0 mmol) in THF (3 mL) and diethyl ether (3
mL) was treated under argon at -50 °C with a solution of the
alkyllithium (8 mmol). The solution was cooled to -78 °C, and
boron trifluoride etherate (0.5 mL) and the silyl ethers 19a -e
(1 mmol) were added. The mixture was allowed to warm to 20
J O9801566