Steric Hindrance Facilitated Synthesis of Enynes
J . Org. Chem., Vol. 63, No. 9, 1998 2857
R(CH
R(CH
for C25
3
)
2
COH), 31.26 (2C, q, R(CH
3
)
2
COH), 30.07 (2C, q,
COH); EI-MS m/z 376 (M , 7), 59 (100). Anal. Calcd
: C, 79.76; H, 7.50. Found: C, 79.64; H, 7.74.
When the reaction was carried out in the presence of 2-methyl-
-butyn-2-ol-4,O-d and pyrrolidine-N-d deuterated 4-d (C-6)
was obtained (50% D).
-(1-Hyd r oxy-1-m eth yleth yl)flu or a n th en e (6). A sus-
workup (Et
2
O), the residue was chromatographed (hexane) to
+
3
)
2
yield 21 as yellow solid (180 mg, 66%): mp (hexane) 56-57
1
H
28
O
3
°C; H NMR (CDCl
3
, 200 MHz) δ 8.57 (d, J ) 16.1 Hz, 1H),
7.73-7.68 (m, 3H), 7.43-7.26 (m, 3H), 5.91 (d, J ) 16.1 Hz,
1H), 0.29 (s, 9H), 0.16 (s, 9H); 13C{ H} NMR (CDCl
1
, 75 MHz;
3
2
1
3
DEPT) δ 143.79 (1C, d, CH), 135.89 (1C, s, Ar), 135.22 (1C, d,
CH), 134.16 (1C, s, Ar), 130.31 (1C, s, Ar), 129.97 (1C, d, CH),
129.84 (1C, d, CH), 127.36 (1C, d, CH), 125.94 (1C, d, CH),
125.06 (1C, d, CH), 119.59 (1C, s, Ar), 109.04 (1C, d, CH),
106.45 (1C, s, CtC), 105.15 (1C, s, CtC), 105.04 (1C, s, CtC),
7
pension of 4 (300 mg, 0.8 mmol) and KOH (450 mg, 8 mmol)
in i-PrOH (10 mL) was stirred at 80 °C for 12 h. The reaction
mixture was poured into H
organic extract was dried (Na
residue was chromatographed (5:1 hexanes-EtOAc) to yield
2
O and extracted (EtOAc). The
2
SO ) and evaporated. The
4
101.26 (1C, s, CtC), 0.14 (3C, q, (CH
3
)
3
Si), 0.06 (3C, q, (CH
Si); EI-MS m/z 346 (M , 63), 73 (100). Anal. Calcd for C22
Si : C, 76.23; H, 7.56. Found: C, 76.22; H, 7.86.
(E)-1-(1-Bu ten -3-yn yl)-8-eth yn yln a p h th a len e (22).
solution of 21 (0.90 g, 2.6 mmol) in CH Cl (10 mL) was treated
with n-Bu NF‚xH O (1.80 g, ca. 6.5 mmol) in CH Cl (20 mL)
a 23 °C for 4 h. The mixture was partitioned between CH Cl
and H O. The organic extract was dried (Na SO ) and the
3
)
26
3
-
-
+
H
1
6
(
4
1
as a brownish solid (131 mg, 63%): mp 114-115 °C; H NMR
CDCl , 200 MHz) δ 8.82 (d, J ) 7.3 Hz, 1H), 7.94-7.81 (m,
H), 7.69-7.56 (m, 2H), 7.41-7.27 (m, 2H), 2.11 (s, 1H, OH),
2
3
A
2
2
1
3
1
.86 (s, 6H); C{ H} NMR (CDCl
3
, 75 MHz; DEPT) δ 144.33
4
2
2
2
(1C, s, Ar), 141.22 (1C, s, Ar), 136.44 (2C, s, Ar), 132.44 (1C,
2
2
s, Ar), 129.78 (1C, s, Ar), 128.63 (1C, d, ArH), 128.10 (1C, d,
ArH), 127.25 (1C, d, ArH), 127.17 (1C, d, ArH), 126.91 (1C, d,
ArH), 126.45 (1C, d, ArH), 124.53 (1C, d, ArH), 120.45 (1C, d,
2
2
4
solvent was evaporated. The residue was chromatographed
(hexane) to yield 22 as a yellow solid (530 mg, 100%): mp 66-
1
ArH), 119.23 (1C, d, ArH), 76.60 (1C, s, ArC(CH
2C, q, ArC(CH OH) (one of the signals corresponding to a
quaternary carbon was not observed); EI-MS m/z 260 (M ,
3
)
2
OH), 29.90
67 °C; H NMR (CDCl
3
, 200 MHz) δ 8.63 (d, J ) 15.9 Hz, 1H),
(
3
)
2
7.87-7.78 (m, 3H), 7.48-7.37 (m, 3H), 5.90 (dd, J ) 15.9, 2.5
+
13 1
Hz, 1H), 3.58 (s, 1H), 3.04 (d, J ) 2.5 Hz, 1H); C{ H} NMR
(CDCl , 75 MHz; DEPT) δ 145.32 (1C, d, ArH), 135.50 (1C, s,
1
8
00). Anal. Calcd for C19
7.32; H, 6.33.
1
H
16O: C, 87.66; H, 6.19. Found: C,
3
Ar), 135.23 (1C, d, ArH), 134.09 (1C, s, Ar), 130.52 (1C, s, Ar),
130.19 (1C, d, ArH), 129.85 (1C, d, ArH), 127.20 (1C, d, ArH),
125.97 (1C, d, ArH), 125.15 (1C, d, ArH), 118.59 (1C, s, Ar),
108.07 (1C, d, ArH), 85.18 (1C, s, RCtCH), 83.63 (1C, d,
-Iod o-8-(tr im eth ylsilyleth yn yl)n a p h th a len e (20).23 To
3 4
a solution of 1 (1.00 g, 2.6 mmol), Pd(PPh ) (150 mg, 0.13
mmol), and CuI (47 mg, 0.26 mmol) in piperidine (5 mL) was
added trimethylsilylacetylene (375 µL, 2.7 mmol) and the
mixture was stirred at 23 °C for 12 h. After the usual workup
RC≡CH), 83.14 (1C, s, RCtCH), 78.13 (1C, d, RC≡CH); EI-
+
MS m/z 202 (M , 100). EI-HRMS m/z Calcd for C16
10
H :
(Et
2
O), the residue was chromatographed (hexane) to yield 20
202.0783. Found: 202.0786.
1
as a colorless oil (0.60 g, 65%): H NMR (CDCl
3
, 200 MHz) δ
F lu or a n th en e (23). Meth od a . A solution of 21 (100 mg,
0.5 mmol) and hydroquinone (ca. 1 mg) in xylene (10 mL) was
stirred at 150 °C for 6 h. The solvent was evaporated, and
the residue was chromatographed (hexane) to yield 23 as a
white solid (65 mg, 65%).
8
7
7
0
.28 (dd, J ) 7.3, 1.3 Hz, 1H), 7.88 (dd, J ) 7.2, 1.3 Hz, 1H),
.79 (dd, J ) 7.0, 1.6 Hz, 1H), 7.78 (dd, J ) 7.8, 1.6 Hz, 1H),
.38 (dd, J ) 7.8, 7.3 Hz, 1H), 7.07 (dd, J ) 7.8, 7.7 Hz, 1H),
1
3
1
.32 (s, 9H); C{ H} NMR (CDCl , 75 MHz; DEPT) δ 142.78
3
(
(
(
(
(
1C, d, ArH), 137.14 (1C, d, ArH), 134.71 (1C, s, Ar), 131.89
1C, s, Ar), 130.62 (1C, d, ArH), 130.09 (1C, d, ArH), 127.02
1C, d, ArH), 125.28 (1C, d, ArH), 122.75 (1C, s, Ar), 107.52
Meth od b. A solution of 21 (50 mg, 0.25 mmol) and CuCl
(5 mg, 0.05 mmol) in pyridine (3 mL) was stirred at 23 °C for
5 h. The reaction mixture was partitioned between Et
10% aqueous HCl solution. The organic extract was dried
(MgSO ) and the solvent was evaporated. The residue was
chromatographed (hexane) to yield 23 as a yellow solid (25
2
O and
1C, s, CtC), 104.19 (1C, s, CtC), 93.14 (1C, s, Ar), -0.56
+
3C, q, (CH
3
)
3
Si); EI-MS m/z 350 (M , 90), 165 (100). Anal.
4
Calcd for C15
.37.
E)-1-(4-Tr im eth ylsilyl-1-bu ten -3-yn yl)-8-(tr im eth ylsi-
lyleth yn yl)n a p h th a len e (21). Meth od a . To a solution of
0 (119 mg, 0.34 mmol), Pd (dba) ‚dba (20 mg, 0.03 mmol) and
AsPh (27.2 mg, 0.07 mmol) in NMP (2 mL) was added a
H15ISi: C, 51.44; H, 4.32. Found: C, 51.47; H,
3
9
1
4
mg, 50%): mp 107-109 °C (lit. mp 110-111 °C); H NMR
(
(CDCl , 200 MHz) δ 7.98-7.82 (m, 6H), 7.70-7.60 (m, 2H),
3
7.43-7.35 (m, 2H).
2
2
3
Ack n ow led gm en t. This work was supported by the
DGICYT (project PB94-0163). We also acknowledge
J ohnson Matthey PLC for a generous loan of palladium
dichloride. J .J .G. acknowledges the receipt of a predoc-
toral fellowship by the Ministerio de Educaci o´ n y
Ciencia. A.F. acknowledges the receipt of a postdoctoral
fellowship by the Universidade de Santiago de Com-
postela.
3
solution of (E)-bis(tributylstannyl)ethene (280 mg, 0.68 mmol)
in NMP (0.5 mL) and the mixture was stirred at 50 °C for 16
h. After the usual workup (Et
graphed (250:1 hexane-CH Cl ) to yield 21 as a yellow oil (70
mg, 60%).
Meth od b. (i) A solution of 20 (300 mg, 0.86 mmol),
Pd (dba) ‚dba (15 mg, 0.026 mmol), and AsPh (21 mg, 0.05
2
O), the residue was chromato-
2 2
2
3
3
mmol) in NMP (5 mL) was treated with (E)-1,2-bis(tributyl-
stannyl)ethene (784 mg, 1.3 mmol) at 50 °C for 2 h. The
mixture was dissolved in THF (30 mL) and was treated at -78
Su p p or tin g In for m a tion Ava ila ble: Full experimental
details and characterization data for E-4, 7-11, 13-16, 18,
°
C with a solution of I
After 30 min the mixture was warmed to 23 °C, diluted with
Et O, and treated with a saturated aqueous Na solution
and a 10% aqueous HCl solution. The organic extract was
dried (MgSO ) and the solvent was evaporated. The residue
was chromatographed (hexane) to yield (E)-1-(2-iodoethenyl)-
-(trimethylsilylethynyl)naphthalene mixed with Bu SnI. (ii)
This crude derivative and Pd (dba) ‚dba (25 mg, 0.02 mmol,
.5 mol %), CuI (15 mg, 0.09 mmol), and PPh (11 mg, 0.04
2
(870 mg, 3.4 mmol) in THF (10 mL).
1
9, 24, and the products of the reaction of 1-iodo-8-phenyl-
1
13
naphthalene with alkyne 2 and copies of the H and C NMR
spectra of 8, 10, 18, 19, 22 (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.
2
2 2 3
S O
4
8
3
2
3
2
3
J O9717853
mmol) in piperidine (5 mL) were treated with trimethylsilyl-
acetylene (120 µL, 0.9 mmol) a 23 °C for 12 h. After the usual
(39) Orchin, M.; Reggel, L. J . Am. Chem. Soc. 1947, 69, 505.