75%) or 4c (471 mg, 2.2 mmol) yielding 439 mg (1.66 mmol, 83%)
of the product as a colourless oil. dH (300 MHz, CDCl3, Me4Si)
0.88 (t, J = 3.60 Hz, 3H, CH3), 1.20–1.40 (m, 8H, 4 × CH2),
1.53 (d, J = 6.45, 3H, CH3-CH), 2.32 (dt, J = 7.50, 0.90 Hz,
2H, C(O)CH2), 5.89 (q, J = 6.45, 1H, CH-O), 7.23–7.38 (m,
5H, ArH).
C(16)HH, C(9)H, C(11)HH), 2.75–2.85 (m, 2H, C(16)HH,
C(8)H), 4.10–4.20 (m, 1H, C(17)H), 6.56 (d, J = 2.75 Hz,
1H, C(4)H), 6.63 (dd, J = 2.75, 8.42 Hz, 1H, C(2)H), 7.16
(d, J = 8.42 Hz, 1H, C(1)H); dC (75 MHz, dioxane-d8, Me4Si)
17.38 (C(13)CH3), 20.44 (CH3-CO), 24.80 (C(15)), 26.95 (C(7)),
28.86 (C(11)), 30.45 (C(8)), 32.31 (C(16)), 33.08 (C(12)), 40.01
(C(6)), 44.49 (C(13)), 46.13 (C(9)), 48.24 (C(14)), 55.02 (OCH3),
79.67 (C(17)), 111.98 (C(2)), 114.18 (C(4)), 126.77 (C(1)), 133.31
Phenyl-acetic acid 1-phenyl-ethyl ester (9d)
=
(C(10)), 138.29 (C(5)), 158.30 (C(3)), 170.79 (C O).
This compound was prepared as described above with 3d
(388 mg, 2.2 mmol) as acyl donor yielding 489 mg (1.60 mmol,
80%) of the product as a colourless oil. dH (300 MHz, CDCl3,
Me4Si) 1.50 (d, J = 6.61, 3H, CH3-CH), 3.62 (s, 2H, CH2), 5.89
(q, J = 6.61, 1H, CH), 7.19–7.35 (m, 10H, ArH).
Acknowledgements
U. H. thanks the Royal Netherlands Academy of Arts and
Sciences (KNAW) for a fellowship. N. C. S., N. C. and F. V.
thank IAESTE for a fellowship. The authors wish to thank
N. J. Broers and V. Verboom for supporting experiments.
Procedure for the one-pot racemisation and acylation of (S)-1 or
(S)-6
References
Neodymium(III), samarium(III) or gadolinium(III) isopropoxide
(0.37 mmol) and zeolite NaA (30 mg, dried at 400 ◦C)
were dissolved and suspended in heptane (12 mL). 1,3,5-
Triisopropylbenzene (0.2 mL) and acetone (15 lL, 0.20 mmol)
were added and the temperature was raised to 50 ◦C. (S)-1 or (S)-
6 (0.24 mL, 2.0 mmol) was added. The reaction was followed by
GC. After complete racemisation (less than 18 h) isopropenyl
acetate (3a) (0.24 mL, 2.2 mmol) was added. Alcohol 1 was
converted into the racemic acetate rac-9a in 15 minutes. Alcohol
6 was converted into its racemic acetate in 20 minutes. The
reaction mixture was concentrated in vacuo and the product
was purified by column chromatography (PE : Et2O 4 : 1).
NdIII + (S)-1 yielded 288 mg (1.76 mmol, 88%) of the
racemic acetate, SmIII + (S)-1 yielded 284 mg (1.74 mmol, 87%),
GdIII + (S)-1 yielded 295 mg (1.80 mmol, 90%), NdIII + (S)-6
yielded 296 mg (1.74 mmol, 87%), SmIII + (S)-6 yielded 289 mg
(1.70 mmol, 85%), GdIII + (S)-6 yielded 306 mg (1.80 mmol,
90%).
1 H. Meerwein and R. Schmidt, Justus Liebigs Ann. Chem., 1925, 444,
221–238.
2 A. Verley, Bull. Soc. Chim. Fr., 1925, 37, 537–542.
3 W. Ponndorf, Angew. Chem., 1926, 29, 138–143.
4 H. Lund, Ber. Dtsch. Chem. Ges., 1937, 70, 1520–1525.
5 R. V. Oppenauer, Recl. Trav. Chim. Pays-Bas, 1937, 56, 137–144.
6 A. L. Wilds, Org. React., 1944, 2, 178–223.
7 C. Djerassi, Org. React., 1953, 6, 207–272.
8 J. F. de Graauw, J. A. Peters, H. van Bekkum and J. Huskens,
Synthesis, 1994, 1007–1017.
9 K. Nishide and M. Node, Chirality, 2002, 14, 759–767.
10 D. Klomp, T. Maschmeyer, U. Hanefeld and J. A. Peters, Chem.
Eur. J., 2004, 10, 2088–2093.
11 J. L. Namy, J. Souppe, J. Collin and H. B. Kagan, J. Org. Chem.,
1984, 49, 2045–2049.
12 E. J. Campbell, H. Zhou and S. T. Nguyen, Org. Lett., 2001, 3, 2391–
2393.
13 T. Ooi, T. Miura, Y. Itagaki, H. Ichikawa and K. Maruoka, Synthesis,
2002, 279–291.
14 D. M. S. Wheeler and M. M. Wheeler, Reductions of steroidal ketones,
chapter 2 of Organic reactions in steroid chemistry Vol I, eds. J. Fried
and J. A. Edwards, Van Nostrand Reinhold Company, New York,
Cincinnati, Toronto, London, Melbourne, pp. 61–110.
15 G. A. Grasa, R. Singh and S. P. Nolan, Synthesis, 2004, 971–985.
16 M. Degueil-Castaing, B. De Jeso, S. Drouillard and B. Maillard,
Tetrahedron Lett., 1987, 28, 953–954.
17 Y.-F. Wang, J. J. Lalonde, M. Momongan, D. E. Bergbreiter and
C.-H. Wong, J. Am. Chem. Soc., 1988, 110, 7200–7205.
18 Y. Kita, Y. Takebe, K. Murata, T. Naka and S. Akai, J. Org. Chem.,
2000, 65, 83–88.
Procedure for one-pot epimerisation and acylation of b-2
Neodymium(III) isopropoxide (8.4 mg, 0.064 mmol) and zeolite
NaA (10 mg, dried at 400 ◦C) were added to toluene (2.2 mL).
Acetone (2.6 lL, 0.04 mmol) was added and the temperature
was raised to 50 ◦C. b-2 (90 mg, 0.32 mmol) was dissolved in the
reaction mixture. After 1 h the temperature was raised to 90 ◦C
and after 24 h isopropenyl acetate (3a) (38 lL, 0.35 mmol) was
added. The reaction was monitored by TLC. Complete acylation
was achieved after 1 h. The mixture was cooled, washed with
an aqueous 1 M HCl solution (5 mL), dried over MgSO4
and concentrated. Column chromatography (PE : MTBE 3 :
1) yielded 41 mg of b-10 (0.12 mmol, 40%) and 34 mg of
a-10 (0.10, 33%), both as white solids.33 b-10: dH (300 MHz,
CDCl3, Me4Si) 0.81 (s, 3H, C-CH3), 1.10–1.60 (m, 7H, C(14)H,
C(6)H2, C(12)HH, C(7)HH, C(11)HH, C(15)HH), 1.60–1.80
(m, 1H, C(12)HH), 1.80–2.00 (m, 2H, C(15)HH, C(7)HH), 1.93
(s, 3H, CH3-CO), 2.05–2.22 (m, 2H, C(16)HH, C(9)H), 2.22–
2.40 (m, 1H, C(11)HH), 2.70–2.90 (m, 2H, C(16)HH, C(8)H),
3.68 (s, 3H, O-CH3), 4.66 (dd, J = 7.61, 8.91 Hz, 1H, C(17)H),
6.56 (d, J = 2.70 Hz, 1H, C(4)H), 6.64 (dd, 1H, J = 2.70,
8.40 Hz C(2)H), 7.14 (d, J = 8.40 Hz, 1H, C(1)H); dC (75 MHz,
dioxane-d8, Me4Si) 12.36 (C(13)CH3), 20.65 (CH3-CO), 23.61
(C(15)), 26.96 (C(7)), 27.97 (C(11)), 30.27 (C(8)), 30.93 (C(16)),
37.57 (C(12)), 39.68 (C(6)), 43.83 (C(13)), 44.76 (C(9)), 50.23
(C(14)), 55.01 (OCH3), 81.64 (C(17)), 111.96 (C(2)), 114.20
(C(4)), 126.69 (C(1)), 133.12 (C(10)), 138.20 (C(5)), 158.27
19 C. Platas-Iglesias, L. Vander Elst, W. Zhou, R. N. Muller, C. F. G. C.
Geraldes, T. Maschmeyer and J. A. Peters, Chem. Eur. J., 2002, 8,
5121–5131.
20 Y. Kita, H. Maeda, F. Takahashi and S. Fukui, J. Chem. Soc., Perkin
Trans. 1, 1993, 2639–2649.
21 Y. Kita, H. Maeda, K. Omori, T. Okuno and Y. Tamura, J. Chem.
Soc., Perkin Trans. 1, 1993, 2999–3005.
22 N. Shibata, M. Matsugi, N. Kawano, S. Fukui, C. Fuijimori, K.
Gotanda, K. Murata and Y. Kita, Tetrahedron: Asymmetry, 1997, 8,
303–310.
23 A. R. Quirt and J. S. Martin, J. Magn. Reson., 1971, 5, 318–327.
24 ftp://davinci.chem.umanitoba.ca/pub/marat/SpinWorks.
25 W.-J. Huang, C.-H. Chen, O. V. Singh, S.-L. Lee and S.-S. Lee, Synth.
Commun., 2002, 32, 3681–3686.
26 L. P. Hill, US 6579985, 2003.
27 A. R. Daniewski, J. Org. Chem., 1975, 40, 3124–3127.
28 J. Smidt, A. Sabel, DE 1277246, 1964.
29 E. S. Rothman and G. G. Moore, J. Org. Chem., 1970, 35, 2351–2353.
30 E. R. H. Jones, G. Eglington, M. C. Whiting and B. L. Shaw, in
Organic Synthesis, Collect. vol. IV, Wiley & Sons, New York, pp.
404–407, 1963.
31 I. I. Lapkin, V. V. Fotin and S. V. Sinani, J. Org. Chem. USSR (Engl.
=
(C(3)), 170.76 (C O); a-10: dH (300 MHz, CDCl3, Me4Si) 0.67
Transl.), 1987, 23, 1199–1200.
(s, 3H, C-CH3), 1.10–1.70 (m, 7H, C(14)H, C(6)H2, C(12)HH,
C(7)HH, C(11)HH, C(15)HH), 1.70–1.95 (m, 3H, C(12)HH,
C(15)HH, C(7)HH), 1.99 (s, 3H, CH3-CO), 2.00–2.40 (m, 3H,
32 B. Zwanenburg, Recl. Trav. Chim. Pays-Bas, 1963, 82, 593–601.
33 C. A. Horiuchi, A. Haga and J. Y. Satoh, Bull. Chem. Soc. Jpn., 1986,
59, 2459–2462.
O r g . B i o m o l . C h e m . , 2 0 0 5 , 3 , 4 8 3 – 4 8 9
4 8 9