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A. F. Barrero et al.
LETTER
(7) Osborn, M.E.; Pegues, J.F.; Paquette, L.A. J. Org. Chem.
1980, 45, 167-168.
(8) Mahoney, W.S.; Brestenky, D.M.; Stryker, J.M. J. Am. Chem.
Soc. 1988, 110, 291-293.
(9) Keinam, E.; Greenspoon, N. J. Am. Chem. Soc. 1986, 108,
7314-7325.
(10) Tanke, R.S.; Crabtree, R,H, Tetrahedron Lett. 1988, 29, 6737-
6740.
(11) Ikeno, T.; Kimura, T.; Ohtsuka, Y.; Yamada, T. Synlett 1999,
96-98.
(12) Freifelder, M. Catalytic Hydrogenation in Organic Synthesis:
Procedures and Commentary; Wiley-Interscience: New York,
1978.
(13) Rylander, P.N. Catalytic Hydrogenation in Organic
Syntheses. Academic Press: New York, 1979.
(14) All new compounds were fully characterized
spectroscopically and had satisfactory high resolution mass
spectroscopy data. Compounds 5a, 6a and 13a are
intermediates of our synthetic research and are a part of
unpublished results. 8a is described in the reference 15, and 8b
is reported in the reference 16.
(d, J=4.1 Hz, 1H, H-6’), 6.31 (dd, J=16.1 and 1.3 Hz, 1H, H-
4’), 6.54 (dd, J=16.1 and 4.1 Hz, 1H, H-5’).
6b 1H NMR (300 MHz, CDCl3) d: -0.04 (s, 3H, Me-Si-CH3),
0.06 (s, 3H, Me-Si-CH3), 0.47 (s, 3H, Me-4a), 0.87 (s, 9H,
CH3-ButSi), 1.12 (s, 3H, Me-1),1.49-1.54 (m, 2H), 1.81-1.96
(m, 6H), 2.09 (sa, 1H, H-5), 3.33 (s, 6H, Me-CH(OCH3)2),
3.60 (s, 3H, Me-COOCH3), 4.28 (t, J=3.0 Hz, 1H, H-7), 4.35
(t, J=5.6 Hz, H-6’), 4.46 (s, 1H, H-1’’A), 4.91 (s, 1H, H-1’’B).
13a 1H NMR (400 MHz, CDCl3) d: 0.50 (s, 3H, Me-4a), 1.04
(ddd, J=17.5, 13.9 and 4.3 Hz, 1H, H-4ax), 1.15 (s, 3H, Me-1),
1.27 (dd, J=12.2 and 2.9 Hz, 1H, H-8a), 1.50 (dt, J=10.8 and
3.5 Hz, 1H, H-1eq), 1.54-1.61 (m, 3H), 1.69-1.90 (m, 4H),
1.91-1.99 (m, 2H), 2.14 (da, J=13.4 Hz, 1H, H-5eq), 2.36 (dt,
J=11.9 and 3.3 Hz, 1H, H-7), 2.42-2.55 (m, 1H, H-2’A), 2.75-
2.85 (m, 1H, H-2’B), 3.27 (s, 6H, Me-CH(OCH3)2), 3.58 (s,
3H, Me-COOCH3), 3.73 (s, 3H, Me-COOCH3), 4.44 (s, 1H,
H-1’’A), 4.82 (s, 1H, H-1’’B), 5.0 (d, J=4.3, 1H, H-6’), 6.64 (d,
J= 4.3 Hz, 1H, H-5’).
13b 1H NMR (300 MHz, CDCl3) d: 0.51 (s, 3H, Me-4a), 1.06
(ddd, J=17.5, 13.4 and 4.1 Hz, 1H, H-4ax), 1.18 (s, 3H, Me-1),
1.29 (dd, J=12.2 and 2.9 Hz, 1H, H-8a), 1.54-1.56 (m, 2H),
1.81 (dt, J=9.8 and 3.3 Hz, H-4eq), 1.85-1.92 (m, 4H), 2.13-
2.20 (m, 2H), 2.38-2.41 (m, 2H), 3.31 (s, 6H, Me-
CH(OCH3)2), 3.61 (s, 3H, Me-COOCH3), 3.70 (s, 3H, Me-
COOCH3), 4.33 (t, J=5.3 Hz, 1H, H-6’), 4.43 (s, 1H, H-1’’A),
4.85 (s, 1H, H-1’’B).
Selected data:
5a 1H NMR (400 MHz, CDCl3) d: 0.01 (s, 3H, Me-Si-CH3),
0.07 (s, 3H, Me-Si-CH3), 0.68 (s, 3H, Me-10), 0.89 (s, 9H,
CH3-ButSi), 1.17 (s, 3H, Me-4), 1.73-2.02 (m, 3H), 2.29 (s,
3H, Me-13), 2.99 (d, J=10.4 Hz, 1H, H-9), 3.65 (s, 3H, Me-
COOCH3), 4.30 (t, J=2.8 Hz, 1H, H-7), 4.48 (s, 1H, H-17),
4.90 (s, 1H, H-17’), 6.09 (d, J=15.8 Hz, 1H, H-12), 6.82 (dd,
J=15.8 and 10.4 Hz, H-11).
(15) Barrero, A. F.; Manzaneda, E.A.; Altarejos, J.; Salido, S.;
Ramos, J.M.; Simmonds, M.S.J.; Blaney, W.M. Tetrahedron
1995, 51, 7435-7450.
5b 1H NMR (300 MHz, CDCl3) d: 0.00 (s, 3H, Me-Si-CH3),
0.05 (s, 3H, Me-Si-CH3), 0.48 (s, 3H, Me-10), 0.87 (s, 9H,
CH3-ButSi), 1.01 (ddd, J=17.5, 13.2 and 4.2 Hz, 1H, H-1ax),
1.12 (s, 3H, Me-4), 2.09 (s, 3H, Me-13), 2.16 (da, J=15 Hz,
1H, H-9), 2.26 (ddd, J=15.2, 9.0 and 6.7 Hz, 1H, H-12B), 2.51
(ddd, J=14, 9.2 and 4.7 Hz, 1H, H-12A), 3.61 (s, 3H, Me-
COOCH3), 4.28 (d, J=3.0 Hz, 1H, H-7), 4.46 (s, 1H, H-17),
4.92 (s, 1H, H-17’).
(16) Barrero, A.F.; Cortés, M.; Manzaneda, E.A.; Cabrera, E.;
Chahboun, R.; Lara, M.; Rivas, A.R. J. Nat. Prod. 1999 (in
press).
(17) Typical experimental procedure:
0.8 g of an aqueous suspension of Raney Nickel (Fluka, cat.
no. 83440) was added to a stirred solution of compound (1.0
mmol) in tetrahydrofuran (10 ml) and the mixture was further
stirred at room temperature (except for compound 1a, which
was reacted at 0°C) for the specified time (Table). The mixture
was diluted with ether and filtered through silica gel, and the
solvent was evaporated to yield the reduced compound.
6a 1H NMR (400 MHz, CDCl3) d: -0.01 (s, 3H, Me-Si-CH3),
0.04 (s, 3H, Me-Si-CH3), 0.47 (s, 3H, Me-4a), 0.86 (s, 9H,
CH3-ButSi), 1.12 (s, 3H, Me-1), 1.13 (ddd, J=17.4, 13.4 and
4.1 Hz, 1H, H-4ax), 1.48-1.55 (m, 2H), 1.77-1.98 (m, 6H), 2.15
(da, J=12.2 Hz, 1H, H-1eq), 2.40 (ddd, J=15.7, 9.2 and 6.6 Hz,
H-2’A), 2.67 (ddd, J=14.0, 9.2 and 4.6 Hz, H-2’B), 3.32 (s, 6H,
Me-CH(OCH3)2), 3.59 (s, 3H, Me-COOCH3), 4.28 (t, J=2.9
Hz, 1H, H-7), 4.47 (s, 1H, H-1’’A), 4.92 (s, 1H, H-1’’B), 4.93
Article Identifier:
1437-2096,E;1999,0,10,1663,1666,ftx,en;L13799ST.pdf
Synlett 1999, No. 10, 1663–1666 ISSN 0936-5214 © Thieme Stuttgart · New York