À
À
C O/C C Bond Formation
5204 5210
collected in Table 3. Further NMR experiments on
a
Varian Inova
a-Benzylg-phenylcyclohexanone: White crystalline solid; m.p. 92 938C;
1H NMR (500 MHz, CDCl3, 258C, TMS) d 1.63 (q, J(H,H) 12.85 Hz,
1H; H3a) 1.92 (m, 1H; H5a) 2.14 2.24 (m, 2H; H5e, H3e), 2.41 (dd,
3J(H,H) 9.0 Hz, 2J(H,H) 14.1 Hz, 1H; CHHPh), 2.53 (m, 2H; H6), 2.75
(m, 1H; H2), 3.00 (tt, 3J(H,H) 3.5 Hz, 3J(H,H) 12.45 Hz, 1H; H4),
500 MHz (the data are available in Table S1 of the Supporting Information)
and some theoretical calculations (Table S2 of the Supporting Information)
show that only the cis diastereomer is obtained from the alkylation reaction
under the experimental conditions used. An exhaustive discussion on this
point can be found in the section ™Structural analysis of a-benzyl-g-
phenylcyclohexanone∫ in the Supporting Information.
3
2
3.32 (dd, J(H,H) 4.6 Hz, J(H,H) 14.1 Hz, 1H; CHHPh), 7.10 7.30
(m, 10H; Csp2H); 13C NMR (500 MHz, CDCl3, 258C, TMS) d 34.93
(cyclohexane CH2 5), 35.10 (CH2), 40.34 (cyclohexane CH2 3), 41.55
(cyclohexane CH2 6), 43.14 (cyclohexane CH4), 51.55 (cyclohexane CH2),
125.84 (Csp2H4), 126.40 (Csp2H4'), 126.53 (Csp2H2',6'), 128.18 (Csp2H3,5),
128.38 (Csp2H3',5'), 128.98 (Csp2H2,6), 139.96 (Csp2H1), 144.42 (Csp2H1'),
Benzylation of a-tetralone: a-Tetralone (1 mmol) and benzyl halide
(1 mmol) were added with stirring to an aqueous solution (10 mL) of 5 Â
10À2 moldmÀ3 CTAB and 1 moldmÀ3 NaOH. The product distribution in
the reaction mixture, recovered after 20 h at room temperature, is reported
in Table 3.
211.18 (CO); MS (70 eV): m/z (%): 264 (89) [M] , 146 (25), 131 (29), 117
(46), 115 (39), 91 (100), 78 (36), 77 (32), 65 (43), 39 (25).
Identification of the products: Compounds were identified by their 1H and
13C spectra (see below). A software package from Advanced Chemistry
Development Inc. that calculates 13C NMR spectra was used to check the
assignments of the chemical shifts.
a,a-Dibenzyl-g-phenylcyclohexanone: White crystalline solid; m.p. 91
928C (hexane); 1H NMR (200 MHz, CDCl3, 258C): d 1.41 (qd, J(H,H)
5.15, J(H,H) 12.45 Hz, 1H) 1.80 3.20 (m, 9H; CH2, CH), 3.35 (d,
J(H,H) 13.3 Hz, 1H) 7.00 7.40 (m, 15H; Csp2H); 13C NMR (200 MHz,
CDCl3, 258C): d 32.24 (cyclohexane CH2 5), 38.54 (cyclohexane CH4),
39.79, 41.02 (CH2), 42.00 (CH2 3 cyclohexane), 44.80 (cyclohexane CH2 6),
54.08 (cyclohexane CH2), 125.84 and 126.14 (Csp2H4), 126.59 (Csp2H4'),
126.30 (Csp2H2',6'), 128.23 (Csp2H3',5'), 127.60/128.00 (Csp2H2,6), 130.03/
130.90 (Csp2H3,5), 136.79/137.92 (Csp2H1), 145.18 (Csp2H1'), 213.86 (CO);
a-(Benzyl)benzyl phenyl ketone:[26] White crystalline solid; m.p. 121.5
122.58C (hexane); 1H NMR (200 MHz, CDCl3, 258C): d 3.06 (dd,
3J(H,H) 7.0, 2J(H,H) 13.8 Hz, 1H; CHaHb), 3.56 (dd, 3J(H,H) 7.5,
2J(H,H) 13.8 Hz, 1H; CHaHb), 4.81 (t, 3J(H,H) 7.3 Hz, 1H; CH), 7.03
7.47/7.85 7.95 (m, 15H; Csp2H); 13C NMR (200 MHz, CDCl3, 258C): d
40.12 (CH2), 55.91 (CH), 126.13 (Ph2 Csp2H4), 127.15 (Ph3 Csp2H4), 132.85
(Ph1 Csp2H4), 128.23 (Ph3 Csp2H3,5), 128.30 (Ph2 Csp2H3,5), 128.48 (Ph1
Csp2H3,5), 128.69 (Ph1 Csp2H2,6), 128.90 (Ph3 Csp2H2,6), 129.14 (Ph2
Csp2H2,6), 136.72 (Ph2 Csp2H1), 139.08 (Ph1 Csp2H1), 139.78 (Ph3 Csp2H1),
199.23 (CO).
MS (70 eV): m/z (%): 354 (5) [M] , 264 (23), 263 (100), 65 (24).
a-Methylbenzyl phenyl ketone:[31a] White crystalline solid; m.p. 49 508C
1
(hexane) [lit.[31b] 538C (ethanol); m.p.[31c] 50 518C (methanol)]; H NMR
(200 MHz, CDCl3, 258C): d 1.65 (d, 3J(H,H) 6.9 Hz, 3H; CH3), 4.80 (q,
3J(H,H) 6.9 Hz, 1H; CH), 7.15 7.55 and 8.05 8.15 (m,10H; Csp2H);
13C NMR (200 MHz, CDCl3, 258C): d 19.91 (CH3), 48.13 (CH), 127.25
(Ph2 Csp2H4), 128.11 (Ph2 Csp2H2,6), 128.82 (Ph2 Csp2H3,5), 129.11 (Ph1
Csp2H3,5), 129.34 (Ph1 Csp2H2,6), 133.12 (Ph1 Csp2H4), 136.76 (Ph2 Csp2H1),
141.87 (Ph1 Csp2H1), 200.48 (CO).
a-Cyclohexylbenzyl phenyl ketone: White crystalline solid; m.p. 119
1208C (hexane) [lit.:[27] m.p. 118 119 (petroleum ether)]; 1H NMR
(200 MHz, CDCl3, 258C): d 0.70 2.00 (m, 10H; CH2 cyclohexane),
3
3
2.37 (qt, J(H,H) 3.3 Hz, J(H,H) 10.6 Hz, 1H; CH cyclohexane), 4.38
(d, 3J(H,H) 10.3 Hz, 1H; CH), 7.10 8.05 (m, 10H; Csp2H); 13C NMR
(200 MHz, CDCl3, 258C): d 26.05, 26.10, 26.40 (cyclohexane CH2 3,4,5),
30.64, 32.51 (cyclohexane CH2 2,6), 41.10 (cyclohexane CH), 59.94 (CH),
126.84 (Ph2 Csp2H4), 132.67 (Ph1 Csp2H4), 128.24, 128.38, 128.55, 128.77
(Csp2H2,3;5,6), 137.66 (Ph2 Csp2H1), 137.93 (Ph1 Csp2H1), 200.54 (CO).
b-Benzyl-a-tetralone:[32] White crystalline solid; m.p. 50 518C (hexane);
1H NMR (200 MHz, CDCl3, 258C): d 1.67 1.86, 2.03 2.16, 2.58 3.00
(m, 6H; CH2), 3.51 (dd, J(H,H) 3.8 Hz, 3J 13.3 Hz, 1H; CH), 7.17 7.35
(m, 7H; Csp2H), 7.47 (td, J(H,H) 1.4, 3J(H,H) 8.2 Hz, 1H; Csp2H) 8.68
3
(dd, J(H,H) 1.1 Hz, J(H,H) 8.5 Hz, 1H; Csp2H); 13C NMR (200 MHz,
Cyclohexyl a[a,b-diphenylethenyl] ether: Colourless liquid; 1H NMR
(200 MHz, CDCl3, 258C): d 0.90 2.0, (m, 10H; CH2 cyclohexane), 3.65
3.85 (m, 1H; CH cyclohexane), 5.95 (s, 1H; CH), 7.10 8.05 (m, 10H;
CDCl3, 258C): d 27.63 (tetralone CH2 3), 28.60 (tetralone CH4), 35.65
(CH2), 49.43 (CH), 126.11 (Csp2H4), 126.60 (tetralone Csp2H7), 127.51
(tetralone Csp2H5), 128.70 (tetralone Csp2H6), 133.26 (tetralone Csp2H8),
128.38 (Csp2H3,5), 129.25 (Csp2H2,6), 132.44 (tetralone Csp2H4a), 140.02
(Csp2H1), 144.00 (tetralone Csp2H8a), 199.36 (CO).
C
sp2H); 13C NMR (200 MHz, CDCl3, 258C): d 26.05, 26.10, 26.40 (cyclo-
hexane CH2 3,4,5), 30.64, 32.51 (cyclohexane CH2 2,6), 41.10 (cyclohexane
CH), 59.94 (CH), 126.84 (Ph2 Csp2H4), 132.67 (Ph1 Csp2H4), 128.24, 128.38,
128.55, 128.77 (Csp2H2,3;5,6), 137.66 (Ph2 Csp2H1), 137.93 (Ph1 Csp2H1),
Benzyl naphthyl ether:[33] White crystalline solid; m.p. 75 778C (hexane)
[lit.[33] 76 778C (ethanol)]; 1H NMR (200 MHz, CDCl3, 258C): d 5.26 (s,
2H; CH2), 6.85 6.95, 7.30 7.60, 7.75 7.90, 8.30 8.45 (m, 12H; Csp2H);
13C NMR (200 MHz, CDCl3, 258C): d 70.07 (CH2), 105.18 (naphthalene
Csp2H2), 120.50 (naphthalene Csp2H4), 122.21 (naphthalene Csp2H5),
125.25 (naphthalene Csp2H8), 125.78 (naphthalene Csp2H4a), 125.84
(naphthalene Csp2H3), 126.46 (naphthalene Csp2H7), 127.38 (benzene
Csp2H3,5), 127.47 (naphthalene Csp2H6), 127.93 (benzene Csp2H4), 128.60
(benzene Csp2H2,6), 134.56 (naphthalene Csp2H8a), 137.17 (benzene
Csp2H), 154.51 (CO).
200.54 (CO); MS (70 eV): m/z (%): 278 (8) [M] , 196 (100), 118 (24), 67
(53), 39 (34).
a-Benzylcyclohexanone:[28] Colourless liquid (b.p.[28a] 1108C at 1 mm Hg);
1H NMR (200 MHz, CDCl3, 258C): d 1.10 2.60 (m, 10H; CH2), 3.19 (dd,
2
3J(H,H) 4.6, J(H,H) 13.6 Hz, 1H; CHaHb), 7.05 7.35 (m, 5H; Csp2H);
13C NMR (200 MHz, CDCl3, 258C): d 24.48 (cyclohexane CH2 4), 27.46
(cyclohexane CH2 5), 32.82 (cyclohexane CH2 3), 34.95 (CH2), 41.50
(cyclohexane CH2 6), 51.73 (CH), 125.35 (Csp2H4), 127.70 (Csp2H3,5),
128.57 (Csp2H2,6), 139.82 (Csp2H1), 211.20 (CO).
a,a-Dibenzylcyclohexanone: White crystalline solid; m.p. 63 658C (hex-
ane) [lit.:[29] 64.5 658C (PhH/EtOH)]; 1H NMR (200 MHz, CDCl3, 258C):
2
Acknowledgements
d 1.60 2.60 (m, 8H; CH2), 2.77 (d, J(H,H) 13.3 Hz, 2H; CH2), 3.17
(d, 2J(H,H) 13.3 Hz, 2H; CH2), 7.12 7.40 (m, 10H; Csp2H); 13C NMR
(200 MHz, CDCl3, 258C): d 20.48 (cyclohexane CH2 4), 25.46 (cyclo-
hexane CH2 5), 33.37 (cyclohexane CH2 6), 39.43 (cyclohexane CH2 3),
41.88 (CH2), 53.65 (C), 126.08 (Csp2H4), 127.73 (Csp2H3,5), 130.50 (Csp2H2,
6), 137.36 (Csp2H1), 213.72 (CO).
We wish to thank MIUR, COFIN99 and CNR, Progetto Finalizzato Beni
Culturali, Rome, for financial support. We are grateful to Prof. C. A.
Bunton for helpful suggestions.
a,e-Dibenzylcyclohexanone: White crystalline solid; m.p. 115 1178C
[29]
(hexane); m.p. 120 1218C (methanol) [lit.
m.p. 121 1228C (meth-
[1] J. March, Advanced Organic Chemistry: Reactions, Mechanisms, and
Structure, 4th ed., Wiley, New York, 1992.
[2] R. Keefe, A. J. Kresge, in The Chemistry of Enols (Ed.: Z. Rappo-
port), Wiley, New York, 1990, pp. 399 480.
[3] J. Clayden, N. Greeves, S. Warren, P. Wothers, Organic Chemistry, 1st
ed., Oxford University Press, New York, 2001, p. 668.
[4] J. K. Whitesell, M. A. Whitesell, Synthesis 1983, 517 536.
[5] P. De Maria, A. Fontana, G. Cerichelli, J. Chem. Soc. Perkin Trans. 2
1997, 2329 2334.
anol)]; cis-a,e-dibenzylcyclohexanone[30] m.p. 124 1258C; trans-a,e-diben-
zylcyclohexanone[30] m.p. 49 518C); 1H NMR (200 MHz, CDCl3, 258C):
d 1.20 2.21 (m, 6H; cyclohexane CH2), 2.40 (dd, 3J(H,H) 8.7,
2J(H,H) 13.8 Hz, 2H; CHaHb), 2.49 2.65 (m, 2H; CH), 3.21 (dd,
3J(H,H) 4.7, 2J(H,H) 13.8 Hz, 2H; CHaHb), 7.12 7.32 (m, 10H; Csp2H);
13C NMR (200 MHz, CDCl3, 258C): d 25.36 (cyclohexane CH2 4), 34.87
(cyclohexane CH2 3,5), 35.51 (CH2), 52.92 (CH), 125.93 (Csp2H4), 128.30
(Csp2H3,5), 129.18 (Csp2H2, 6), 140.60 (Csp2H1), 212.90 (CO).
Chem. Eur. J. 2002, 8, No. 22
¹ 2002 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
0947-6539/02/0822-5209 $ 20.00+.50/0
5209