Reaction of [2.2]Metacyclophanes with Brominating Agents
J . Org. Chem., Vol. 61, No. 15, 1996 5107
yield (688 mg, 2.37 mmol). An analytical sample was obtained
as colorless prisms by recrystallization from hexane: mp 120-
122 °C; IR (KBr) νmax 2980, 2890, 1600, 1480, 1460, 1445, 1360,
J ) 2.6, 4.0, 12.0 Hz, 2 H, C2H4), 3.89 (s, 1 H, ArH), 4.61, 5.62
(d, J ) 13.9 Hz, each 1 H, olefin), 7.10 (s, 2 H, ArH), 7.14 (s,
3 H, ArH); MS m/z 370 (M+, 50), 368 (M+, 40), 185 (100). Anal.
Calcd for C22H25Br: C, 71.54; H, 6.82. Found: C, 71.28; H,
6.89.
1280, 1180, 990, 950, 920, 895, 865, 790, 760, 720 cm-1
;
1H
t
NMR (CDCl3) δ 1.37 (s, 9 H, Bu), 2.18 (dt, J ) 5.0, 11.9 Hz,
2 H, C2H4), 2.76 (dt, J ) 4.3, 11.9 Hz, 2 H, C2H4), 2.89 (ddd, J
) 2.6, 5.0, 11.9 Hz, 2 H, C2H4), 3.00 (ddd, J ) 2.6, 4.3, 11.9
Hz, 2 H, C2H4), 3.86 (s, 1 H, ArH), 4.38 (dd, J ) 10.9, 17.8 Hz,
1 H, olefin), 4.64 (dd, J ) 2.6, 17.8 Hz, 1 H, olefin), 4.73 (dd,
J ) 2.6, 10.9 Hz, 1 H, olefin), 7.02-7.12 (m, 3 H, ArH), 7.10
(s, 2 H, ArH); MS m/z 290 (M+, 39), 185 (100). Anal. Calcd
for C22H26: C, 90.98; H, 9.02. Found: C, 91.13; H, 9.02.
(E )-5-t er t -Bu t yl-8-(2-p h e n yle t h e n yl)[2.2]m e t a cyclo-
p h a n e ((E)-3). To a solution of diethyl benzylphosphonate
(913 mg, 4.0 mmol) in dry tetrahydrofuran (10 mL) was added
dropwise a hexane solition of n-butyllithium solution (2.67 mL,
1.5 M, 4.0 mmol) within 1 min at room temperature under
argon. After the reaction mixture was stirred for 10 min, a
solution of 1 (585 mg, 2.0 mmol) in dry tetrahydrofuran (2 mL)
was added dropwise within 1 min. After the reaction mixture
had been stirred for 1 h, it was poured into ice-water and
extracted with ether. The extracts were washed with water,
dried over magnesium sulfate, and evaporated in vacuo. The
residue was purified by column chromatography (hexane-
ether 19:1), giving (E)-3 in 85% yield (620 mg, 1.69 mmol). An
analytical sample was obtained as colorless prisms by recrys-
tallization from hexane: mp 105-106 °C; IR (KBr) νmax 2980,
8-(2-Br om o-1-m e t h oxye t h yl)-5-t er t -b u t yl[2.2]m e t a -
cyclop h a n e (7). To a suspension of 2 (145 mg, 0.5 mmol) in
methanol (5 mL) was added BTMABr3 (195 mg, 0.5 mmol) at
room temperature. After the reaction mixture was stirred for
5 min, it was poured into 10% aqueous sodium thiosulfate
solution and extracted with ether. The extracts were washed
with water, dried over magnesium sulfate, and evaporated in
vacuo. The residue was purified by column chromatography
(hexane-ether 79:1), giving 7 in 85% yield (170 mg, 0.424
mmol). An analytical sample was obtained as colorless prisms
by recrystallization from hexane: mp 40-42 °C; IR (KBr) νmax
2960, 2930, 2860, 1590, 1475, 1360, 1285, 1210, 1180, 1105,
870, 785, 715 cm-1; 1H NMR (CDCl3) δ 1.36 (s, 9 H, tBu), 2.11-
2.36 (m, 2 H, C2H4), 2.53 (dd, J ) 3.0, 10.9 Hz, 1 H, CH2Br)
2.69 (dt, J ) 4.3, 12.2 Hz, 1 H, C2H4), 2.85-3.11 (m, 6 H, C2H4
and CH2Br), 2.94 (s, 3 H, OMe), 3.42 (dd, J ) 3.0, 7.6 Hz, 1 H,
CHOMe), 3.52 (s, 1 H, ArH), 6.95-7.13 (m, 5 H, ArH); MS
m/z 402 (M+, 10), 400 (M+, 10), 263 (100). Anal. Calcd for
C23H29BrO: C, 68.82; H, 7.28. Found: C, 68.66; H, 7.41.
Tr ea tm en t of (E)-3 w ith BTMABr 3. Using the procedure
for the treatment of 2 with BTMABr3, (E)-3 (293 mg, 0.8 mmol)
was converted to 8a in 34% yield (121 mg, 0.272 mmol) and
8b in 51% yield (182 mg, 0.409 mmol) by treatment with
BTMABr3 (390 mg, 0.8 mmol) in dichloromethane (8 mL) for
90 h. The products were separated by column chromatography
(hexane).
1590, 1475, 1440, 1360, 1180, 965, 865, 780, 760, 750, 740,
t
715, 690 cm-1
;
1H NMR (CDCl3) δ 1.39 (s, 9 H, Bu), 2.18-
2.27, 2.76-3.04 (m, 8 H, C2H4), 4.00 (s, 1 H, ArH), 4.80, 5.94
(d, J ) 16.5 Hz, each 1 H, olefin), 6.98-7.29 (m, 10 H, ArH);
MS m/z 366 (M+, 100), 309 (M+ - Bu, 31). Anal. Calcd for
t
Similarly, compounds 8a and 8b were obtained from (Z)-3
as shown in Table 2.
C28H30: C, 91.75; H, 8.25. Found: C, 91.41; H, 8.30.
(Z)-5-t er t -Bu t yl-8-(2-p h e n yle t h e n yl)[2.2]m e t a cyclo-
p h a n e ((Z)-3). A solution of (E)-3 (183 mg, 0.5 mmol) in
degassed benzene (7 mL) was irradiated with a high-pressure
mercury lamp at 5 °C for 1 h under argon. The reaction
mixture was evaporated in vacuo, and the residue was purified
by column chromatography (hexane-ether 39:1), giving (Z)-3
in 70% yield (128 mg, 0.349 mmol) and unchanged (E)-3 in
10% yield (18 mg, 0.049 mmol). An analytical sample of (Z)-3
was obtained as colorless prisms by recrystallization from
hexane: mp 105-106 °C; IR (KBr) νmax 2980, 2870, 1595, 1495,
1475, 1440, 1355, 1180, 780, 715, 690 cm-1; 1H NMR (CDCl3)
(E )-8-(2-Br om o-2-p h e n yle t h e n yl)-5-t er t -b u t yl[2.2]-
m eta cyclop h a n e (8a ): colorless prisms (hexane); mp 140-
141 °C; IR (KBr) νmax 2970, 2940, 1590, 1475, 1435, 1360, 1175,
950, 890, 870, 790, 770, 720, 695 cm-1; 1H NMR (CDCl3) δ 1.30
t
(s, 9 H, Bu), 2.15 (dt, J ) 4.6, 12.2 Hz, 2 H, C2H4), 2.52 (dt, J
) 4.0, 12.2 Hz, 2 H, C2H4), 2.72 (ddd, J ) 2.6, 4,6, 12.2 Hz, 2
H, C2H4), 3.01 (ddd, J ) 2.6, 4.0, 12.2 Hz, 2 H, C2H4), 3.90 (s,
1 H, ArH), 4.43 (s, 1 H, olefin), 6.80-7.23 (m, 10 H, ArH); MS
m/z 446 (M+, 59), 444 (M+, 50), 57 (100). Anal. Calcd for
C28H29Br: C, 75.50; H, 6.56. Found: C, 75.27; H, 6.56.
t
(Z)-8-(2-Br om o-2-p h e n yle t h e n yl)-5-t er t -b u t yl[2.2]-
m eta cyclop h a n e (8b): colorless prisms (hexane); mp 38-40
°C; IR (KBr) νmax 2975, 2930, 1590, 1490, 1470, 1435, 1360,
1230, 1180, 900, 870, 785, 750, 715, 690 cm-1; 1H NMR (CDCl3)
δ 1.39 (s, 9 H, Bu), 2.20 (dt, J ) 4.6, 12.2, 2 H, C2H4), 2.57
(dt, J ) 4.0, 12.2 Hz, 2 H, C2H4), 2.78 (ddd, J ) 3.0, 4.6, 12.2
Hz, 2 H, C2H4), 2.99 (ddd, J ) 3.0, 4.0, 12.2 Hz, 2 H, C2H4),
3.81, 5.87 (d, J ) 12.5 Hz, each 1 H, olefin), 3.94 (s, 1 H, ArH),
t
6.65-7.18 (m, 10 H, ArH); MS m/z 366 (M+, 100), 351 (M+
-
δ 1.40 (s, 9 H, Bu), 2.25, 2.56 (dt, J ) 4.6, 12.2 Hz, each 2 H,
C2H4), 2.98, 3.04 (ddd, J ) 2.6, 4.6, 12.2 Hz, each 2 H, C2H4),
3.93 (s, 1 H, ArH), 4.58 (s, 1 H, olefin), 7.15-7.30 (m, 10 H,
ArH); MS m/z 446 (M+, 37), 444 (M+, 31), 57 (100). Anal. Calcd
for C28H29Br: C, 75.50; H, 6.56. Found: C, 75.36; H, 6.62.
Me, 25). Anal. Calcd for C28H30: C, 91.75; H, 8.25. Found:
C, 92.11; H, 8.35.
Gen er a l P r oced u r e for Tr ea tm en t of 2 w ith BTMABr 3.
To a solution of 2 (581 mg, 2.0 mmol) in dichloromethane (20
mL) was added BTMABr3 (780 mg, 2.0 mmol) at room
temperature. After the reaction mixture was stirred at room
temperature for 5 min, it was poured into 10% aqueous sodium
thiosulfate solution and extracted with ether. The extracts
were washed with water, dried over MgSO4, and evaporated
in vacuo. The residue was purified by column chromatography
(hexane), giving 6 in 99% yield (729 mg, 1.97 mmol).
Gen er a l P r oced u r e for Tr ea tm en t of 2 w ith Br 2. To a
solution of 2 (581 mg, 2.0 mmol) in carbon tetrachloride (20
mL) was added a solution of bromine in carbon tetrachloride
(4 mL, 0.5 M, 2.0 mmol) at room temperature. After the
reaction mixture was stirred for 5 min, it was poured into 10%
aqueous sodium thiosulfate solution and extracted with ether.
The extracts were washed with water, dried over magnesium
sulfate solution, and evaporated in vacuo. The residue was
purified by column chromatography (hexane), giving 6 in 99%
yield (731 mg, 1.98 mmol).
(E)-5-ter t-Bu tyl-8-[2-(2-ter t-bu tyl-4,5,9,10-tetr a h yd r o-1-
p yr en yl)eth en yl][2.2]m eta cyclop h a n e (9). Using the pro-
cedure for the reaction of 2 with BTMABr3, (E)-4 (750 mg,
1.357 mmol) was converted to 9 in 50% yield (372 mg, 0.675
mmol), along with unchanged (E)-4 in 29% yield (219 mg, 0.396
mmol), by treatment with BTMABr3 (529 mg, 1.357 mmol) in
dichloromethane (14 mL) for 4 h. The products were separated
by column chromatography (hexane-toluene 19:1). An ana-
lytical sample of 9 was obtained as colorless prisms by
recrystallization from hexane: mp 222-223 °C; IR (KBr)
νmax 2970, 2940, 2870, 1480, 1430, 1360, 1260, 1180, 980, 870,
780, 750, 715 cm-1; 1H NMR (CDCl3) δ 1.25, 1.41 (s, each 9 H,
tBu), 2.10-2.31 (m, 2 H, C2H4), 2.61-3.06 (m, 14 H, C2H4),
3.83 (s, 1 H, ArH), 4.29, 6.14 (d, J ) 16.8 Hz, each 1 H, olefin),
6.85-7.20 (m, 9 H, ArH); 13C NMR (CDCl3) δ 27.15, 28.43,
28.77, 28.81 (t, CH2), 31.47, 31.63 (q, C(CH3)3), 34.36, 36.08
(s, C(CH3)3), 37.14, 41.69 (t, CH2), 123.36, 123.47, 125.46,
125.73, 125.98, 126.72, 126.83 (d, ArCH), 128.55, 130.91,
132.15 (s, ArC), 133.53 (d, R-olefin), 134.38, 134.52 (s, ArC),
134.57 (d, 16-ArCH), 134.84 (d, â-olefin), 135.27, 135.42,
137.02, 138.65, 144.13, 147.33, 151.03 (s, ArC); MS m/z 550
(M+, 100), 57 (100). Anal. Calcd for C42H46: C, 91.58; H, 8.42.
Found: C, 91.50; H, 8.23.
(E )-8-(2-Br om oe t h e n yl)-5-t er t -b u t yl[2.2]m e t a cyclo-
p h a n e (6): colorless prisms (hexane); mp 127-129 °C; IR
(KBr) νmax 2990, 2950, 2890, 1600, 1480, 1360, 1230, 1180, 935,
1
t
790, 720 cm-1; H NMR (CDCl3) δ 1.36 (s, 9 H, Bu), 2.18 (dt,
J ) 5.0, 12.0 Hz, 2 H, C2H4), 2.66 (dt, J ) 4.0, 12.0 Hz, 2 H,
C2H4), 2.91 (ddd, J ) 2.6, 5.0, 12.0 Hz, 2 H, C2H4), 3.02 (ddd,