A. Maercker et al. / Tetrahedron 60 (2004) 8245–8256
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60–62 8C, recrystallized from ethanol. 1H NMR (200 MHz)
d 0.70 (s, 1H, H-4endo), 1.11 (s, 1H, H-4exo), 1.58 (2!s, 2!
3H, 2!CH3), 7.13–7.26 (m, 10H, aryl-H). 13C NMR
(50 MHz) d 9.6 (CH3), 17.3 (C-1/3), 34.1 (C-4), 60.5 (C-2),
125.8/125.9 (Car-4), 127.8/128.2 (Car-3), 129.4/129.8 (Car-
2), 140.4/142.0 (Car-1). Calcd for C18H18 (Mr 234.34): C,
92.26%,H, 7.74%; found C, 92.07%,H, 7.90%.
(200 MHz) d 1.11 (t, JZ7.4 Hz, 3H, 4-CH3), 1.86 (s, 3H,
2-CH3), 2.16 (q, JZ7.4 Hz, 2H, CH2), 5.25 (s, 1H, ]CH),
7.13–7.34 (m, 5H, aryl-H). 13C NMR (50 MHz) d 12.7
(C-4), 17.7 (2-CH3), 33.4 (C-3), 123.5 (C-1), 125.7 (Car-4),
127.9 (Car-3), 128.8 (Car-2), 138.7 (Car-1), 140.8 (C-2). MS
m/z 146 (MC, 50), 132 (11), 131 (100), 129 (15), 128 (9),
117 (15), 116 (16), 115 (25), 91 (44), 65 (7). 2-Benzyl-1-
butene (43a00, H instead of Li) (21%): 1H NMR (200 MHz) d
1.02 (t, JZ7.4 Hz, 3H, CH3), 1.97 (q, JZ7.4 Hz, 2H,
3-CH2), 3.34 (s, 2H, Ph-CH2), 4.73/4.81 (2!m, 2!1H,
]CH2), 7.15–7.31 (m, 5H, aryl-H). 13C NMR (50 MHz) d
12.2 (C-4), 28.1 (C-3), 43.2 (Ph-CH2), 109.8 (C-1), 125.9
(Car-4), 128.2 (Car-3), 128.9 (Car-2), 139.9 (Car-1), 150.7
(C-2). MS m/z 146 (MC, 33), 131 (30), 129 (7), 118 (10),
117 (100), 115 (29), 104 (21), 91 (58), 65 (15), 39 (10).
4.3.9. Reaction of phenylspiropentane (41a) with lithium
metal. To 0.80 g (0.11 mol) of lithium were added at
K90 8C a solution of 1.9 g (13 mmol) of 41a in 20 mL of
THF. The mixture, when allowed to slowly warm up, turned
red at K50 8C and was stirred at K30 8C for 2 h. After
filtering off the excess of lithium metal, the reaction was
quenched with 3.2 g (25 mmol) of dimethyl sulfate, excess
of dimethyl sulfate was destroyed as usual with 20%
aqueous ammonia solution and the remainder was purified
after the usual workup by bulb-to-bulb condensation to
afford 1.5 g (8.6 mmol, 66%) of crude product. The main
component was isolated by distillation at 35–44 8C
(0.01 Torr) and further purified by preparative gas chroma-
tography. 2-(1-Phenylethyl)-1-pentene (43a00, Me instead of
Li): 1H NMR (200 MHz) d 0.83 (t, JZ7.3 Hz, 3H, 5-CH3),
1.36 (d, JZ7.1 Hz, 3H, CH–CH3), 1.41 (m, 2H, 4-CH2),
1.85 (t, JZ8.4 Hz, 2H, 3-CH2), 3.39 (q, JZ7.1 Hz, 1H,
CH), 4.89/4.93 (2!m, 2!1H, ]CH2), 7.21 (m, 5H, aryl-
H). 13C NMR (50 MHz) d 13.9 (C-5), 20.8 (CH–CH3), 21.8
(C-4), 37.2 (C-3), 45.3 (CH–CH3), 108.6 (C-1), 126.1 (Car-
4), 127.6 (Car-3), 128.6 (Car-2), 145.6 (Car-1), 153.1 (C-1).
MS m/z 174 (MC, 19), 131 (100), 117 (49), 115 (21), 105
(32), 91 (32), 77 (19), 41 (25), 39 (25), 27 (29). Calcd for
C13H18 (Mr 174.14): C, 89.59%, H, 10.41%; found C,
89.60%, H, 10.40%.
4.3.10. Reaction of 1,1-diphenylspiropentane (41b) with
lithium metal. 0.55 g (2.5 mmol) of 41b in 15 mL of THF
were added to 0.50 g (71 mmol) of lithium at K60 8C. After
1.5 h at K30 8C the excess of lithium was filtered off and the
solution was quenched with 2.0 mL (20 mmol) of dimethyl
sulfate in 5 mL of THF at K70 8C. After the usual workup
and bulb-to-bulb condensation 0.50 g (2.0 mmol, 80%) of
crude product were obtained. 2-(1,1-Diphenylethyl)-1-
pentene (43b00, Me instead of Li) (71%) was characterized
1
as follows: H NMR (200 MHz) d 0.83 (t, JZ7.3 Hz, 3H,
5-CH3), 1.41 (m, 2H, 4CH2), 1.88 (s, 3H, Ph2C–CH3), 1.92
(t, JZ7.6 Hz, 2H, 3-CH2), 4.66/5.08 (2!br s, 2!1H,
]CH2), 7.14–7.31 (m, 10H, aryl-H). 13C NMR (50 MHz) d
14.2 (5-CH3), 22.0 (C-4), 27.8 (Ph2C–CH3), 35.4 (C-3),
54.2 (Ph2C), 112.2 (C-1), 125.8 (Car-4), 127.7 (Car-3), 128.5
(Car-2), 147.3 (Car-1), 155.5 (C-2). MS m/z 250 (MC, 17),
207 (100), 181 (81), 166 (21), 165 (31), 129 (42), 115 (19),
103 (37), 91 (60), 77 (21). Calcd for C19H22 (Mr 250.17): C,
91.14%, H, 8.86%; found C, 90.98%, H, 8.81%. Further-
more the following structures were made plausible by their
mass spectra. 2-Ethyl-1,1-diphenyl-1-pentene (43b0, Me
instead of Li) (2%). MS m/z 250 (MC, 12), 234 (51), 219
(54), 207 (16), 178 (18), 143 (26), 141 (19), 129 (25), 128
(19), 115 (33), 91 (100). 2-Ethyl-1,1-diphenyl-1,3-buta-
diene (44b0, Me instead of Li) (5%). MS m/z 234 (MC, 84),
219 (18), 206 (30), 205 (100), 204 (26), 203 (35), 202 (28),
191 (18), 101 (16), 91 (38). 2-(1,1-Diphenylethyl)-1-butene
(2%). MS m/z 236 (MC, 18), 207 (100), 181 (66), 179 (17),
166 (17), 165 (27), 129 (36), 128 (16), 103 (36), 91 (48).
Another reaction was performed on the same scale and
quenched with 2.5 mL of methanol-d1 in 10 mL of THF.
After the usual workup 1.7 g (11 mmol, 88%) of crude
product were obtained after bulb-to-bulb condensation, the
two components were further purified by preparative gas
chromatography. (E)-2-(Methyl-d1)-1-phenyl-1-butene-4-
1
d1 (43a0, D instead of Li) (70%). H NMR (200 MHz) d
1.09 (tt, JZ7.4 Hz, JHDZ2.0 Hz, 2H, 4-CH2D), 1.84 (t,
JHDZ1.7 Hz, 2H, 2-CH2D), 1.41 (m, 2H, 4-CH2), 2.18 (t,
JZ7.4 Hz, 2H, 3-CH2), 7.16–7.34 (m, 5H, aryl-H). 13C
NMR (50 MHz) d 12.4 (equal intensity triplet, 4-CH2D),
17.4 (equal intensity triplet, 2-CH2D), 33.3 (C-3), 123.5
(C-1), 125.7 (Car-4), 127.9 (Car-3), 128.8 (Car-2), 138.7 (Car-
1), 140.7 (C-2). MS m/z 148 (MC, 49), 133 (13), 132 (100),
130 (13), 118 (12), 117 (12), 116 (22), 115 (11), 92 (23), 91
(27). 2-(1-Deuteriobenzyl)-1-butene-4-d1 (43a00, D instead
Two further reactions were performed in the same manner,
starting with 0.55 g (2.5 mmol) of 41b and 1.0 g (0.14 mol)
of lithium. One reaction mixture was quenched with 2.0 mL
of methanol to afford 0.43 g (1.9 mmol 78%) of crude
product, the other with 2.0 mL of methanol-d1 yielded
0.48 g (2.1 mmol, 86%) after bulb-to-bulb condensation.
The following mass spectra were obtained. 2-Methyl-1,1-
diphenyl-1-butene (43b0, H instead of Li) (34%). MS m/z
222 (MC, 97), 207 (46), 193 (37), 179 (23), 178 (35), 165
(34), 129 (100), 128 (27), 115 (27), 91 (62). 2-Benzhydryl-
1-butene (43b00, H instead of Li) (34%). MS m/z 222 (MC,
56), 193 (100), 179 (26), 178 (22), 167 (64), 165 (60), 152
(27), 129 (20), 115 (61), 91 (28). 2-Methyl-1,1-diphenyl-
1,3-butadiene (44b0, H instead of Li) (10%). MS m/z 220
(MC, 100), 205 (98), 204 (26), 203 (34), 202 (30), 191 (42),
178 (17), 128 (16), 101 (23).
1
of Li) (18%). H NMR (200 MHz) d 1.00 (tt, JZ7.4 Hz,
JHDZ2.0 Hz, 2H, 4-CH2D), 1.97 (t, JZ7.4 Hz, 2H, 3-CH2),
3.32 (br s, 1H, CH), 4.73/4.82 (2!m, 2!1H, ]CH2),
7.14–7.33 (m, 5H, aryl-H). 13C NMR (50 MHz) d 11.9
(equal intensity triplet, 4-CH2D), 28.1 (C-3), 42.9 (equal
intensity triplet, CHD), 109.8 (C-1), 126.0 (Car-4), 127.2
(Car-3), 128.9 (Car-2), 139.9 (Car-1), 150.6 (C-2). MS m/z
148 (MC, 32), 133 (11), 132 (21), 119 (11), 118 (100), 116
(21), 105 (14), 92 (44), 91 (12), 66 (9).
Another reaction was performed as described above,
methanol was used instead for quenching. (E)-2-Methyl-1-
1
phenyl-1-butene (43a0, H instead of Li) (74%): H NMR