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L. Allmendinger et al.
LETTER
Tetrahedron 1999, 55, 14635. (d) Walker, J. R.; Curley, R.
W. Jr. Tetrahedron 2001, 57, 6695. (e) Moutevelis-
Minakakis, P.; Sinanoglou, C.; Loukas, V.; Kokotos, G.
Synthesis 2005, 933. (f) For a recent review covering the
oxidative degradation of benzene rings see: Mander, L. N.;
Williams, C. M. Tetrahedron 2003, 59, 1105.
(17) For an alternative stereoselective approach to (2E,4Z)-hexa-
2,4-dienoic acid (14), see ref. 5b.
(18) Smith, A. B.; Pitram, S. M.; Boldi, A. M.; Gaunt, M. J.;
Sfouggatakis, C.; Moser, W. H. J. Am. Chem. Soc. 2003,
125, 14435.
(19) (a) Barker, P. L.; Gendler, P. L.; Rapoport, H. J. Org. Chem.
1981, 46, 2455. (b) Josse, O.; Labar, D.; Marchand-
Brynaert, J. Synthesis 1999, 404.
(20) For a previous synthesis of 3-aminopropionamidine, starting
from 3-aminopropionitril, see: Hilgetag, G.; Paul, H.;
Günther, J.; Witt, M. Chem. Ber. 1964, 97, 704.
(12) (a) Yoshifuji, S.; Tanaka, K.; Nitta, Y. Chem. Pharm. Bull.
1985, 33, 1749. (b) Tanaka, K.; Yoshifuji, S.; Nitta, Y.
Chem. Pharm. Bull. 1988, 36, 3125.
(13) (a) In addition to product 10, its N-formyl derivative 3-tert-
butoxycarbonylformylamino-5-tert-butyldimethylsilyloxy-
6-nitrohexanoic acid (5% yield) and trace amounts (<1%) of
4-tert-butoxycarbonylamino-2-tert-butyldimethyl-
silyloxyhexanedioic acid, the latter indicating a Nef-type
reaction at the nitromethyl group, were obtained.
(21) Lee, H. K.; Ten, L. N.; Pak, C. S. Bull. Korean Chem. Soc.
1998, 19, 1148.
(22) Spectroscopic data of sperabillin A (3a)2c: [a]D23 –11.4 (c 0.4
in H2O), lit.2c [a]D23 –11 (c 1.1 in H2O). 1H NMR (500 MHz,
D2O): d = 1.77 (1 H, ddd, J = 4.5, 10.0, 15.0 Hz), 1.87 (3 H,
d, J = 7.2 Hz), 1.87 (1 H, m), 2.68 (2 H, t, J = 6.6 Hz), 2.74
(2 H, m), 3.33 (1 H, dd, J = 6.6, 14.0 Hz), 3.39 (1 H, dd,
J = 4.5, 14.0 Hz), 3.55 (1 H, dt, J = 6.6, 14.0 Hz), 3.59 (1 H,
dt, J = 6.7, 14.0 Hz), 3.86 (1 H, m), 4.00 (1 H, m), 6.02 (1 H,
dq, J = 7.2, 10.8 Hz), 6.07 (1 H, d, J = 15.1 Hz), 6.23 (1 H,
t, J = 10.8 Hz), 7.56 (1 H, dd, J = 11.8, 15.1 Hz). 13C NMR
(100 MHz, D2O): d = 16.0, 35.3, 38.0, 39.2, 39.8, 47.8, 49.1,
69.1, 125.1, 129.6, 139.4, 139.5, 171.7, 172.4, 174.7.
(23) Spectroscopic data of sperabillin C (3c)2c: [a]D23 –10.2 (c 0.4
in H2O), lit.2c [a]D20 –11 (c 0.7 in H2O). 1H NMR (500 MHz,
D2O): d = 1.75 (1 H, ddd, J = 4.7, 10.0, 15.0 Hz), 1.83 (3 H,
d, J = 5.5 Hz), 1.87 (1 H, ddd, J = 3.1, 7.5, 15.0 Hz), 2.67 (2
H, t, J = 6.7 Hz), 2.73 (2 H, d, J = 7.0 Hz), 3.30 (1 H, dd,
J = 6.5, 14.0 Hz), 3.37 (1 H, dd, J = 4.7, 14.0 Hz), 3.57 (2 H,
m), 3.85 (1 H, m), 3.98 (1 H, m), 5.97 (1 H, d, J = 15.5 Hz),
6.26 (2 H, m), 7.13 (1 H, dd, J = 9.7, 15.5 Hz). 13C NMR
(100 MHz, D2O): d = 20.7, 35.3, 38.0, 39.2, 39.8, 47.8, 49.1,
69.1, 122.9, 132.0, 143.2, 145.4, 171.6, 172.5, 174.7.
Application of the reaction conditions [2.2 mol% RuCl,
NaIO4 (18 equiv), CCl4–MeCN–H2O = 2:2:3, r.t.]
previously developed by Sharpless and co-workers (see ref.
13b) gave the oxidation product 10 in a 41% yield together
with 24% of the N-formyl derivative mentioned above.
(b) Carlsen, P. H. J.; Katsuki, T.; Martin, V. S.; Sharpless, K.
B. J. Org. Chem. 1981, 46, 3936.
(14) In the absence of sodium hydrogen carbonate a somewhat
lower yield (56%) of product 10 was obtained.
(15) Spectroscopic data of compound 4: [a]D20 +20.8 (c 0.95 in
CH2Cl2). 1H NMR (500 MHz, MeOH-d4): d = 0.13 (3 H, s),
0.15 (3 H, s), 0.92 (9 H, s), 1.43 (9 H, sbr), 1.78 (2 H, m), 2.31
(1 H, dd, J = 14.9, 7.7 Hz), 2.39 (1 H, dd, J = 14.9, 4.7 Hz),
3.01 (1 H, dd, J = 13.0, 4.1 Hz), 3.06 (1 H, dd, J = 13.0, 4.9
Hz), 3.85 (1 H, m), 4.18 (1 H, m), 4.09 (1 H, m). 13C NMR
(100 MHz, MeOH-d4): d = –5.0, 18.4, 25.9, 28.3, 40.0, 43.5,
45.2, 45.8, 67.7, 79.6, 157.1, 178.6.
(16) Rossi, R.; Carpita, A.; Quirici, M. G.; Gaudenti, M. L.
Tetrahedron 1982, 38, 631.
Synlett 2005, No. 17, 2615–2618 © Thieme Stuttgart · New York