Organic & Biomolecular Chemistry
Paper
(80 : 20)]; νmax (neat)/cm−1 2970, 2930, 1685, 1515; 1H NMR
(400 MHz, CDCl3, rotamers) δ = 6.75–6.58 (5H, m, 5 × CH),
5.93 (2H, s, OCH2O), 5.18–5.01 (1H, m, CH), 4.28–4.26 (0.5H,
m, CH), 4.05–4.00 (0.5H, m, CH), 3.86 (6H, s, 2 × CH3),
3.29–3.17 (1H, m, CH), 2.98–2.59 (4H, m, 3 × CH), 2.10–2.00
(2H, m, 2 × CH), 1.50 (9H, s, t-Bu); 13C NMR (100 MHz, CDCl3,
rotamers) δ = 154.9, 147.7, 147.4, 145.6, 136.0 & 135.7, 130.1,
129.6, 126.3 & 125.9, 120.9, 111.6, 110.2 & 109.9, 108.7 & 108.1,
100.7, 79.9 & 79.4, 56.0 & 55.9, 54.4 & 53.6, 39.1 & 38.7, 36.9,
32.7, 28.5, 28.1 & 27.9; HRMS (ES) Found: MNa+, 464.2032
C25H31NO6Na requires MNa+ 464.2049, LRMS m/z (ES) 464
(100%).
W. Yuan, J. Zhang, C. Zhu and S. Ma, Angew. Chem., Int.
Ed., 2014, 53, 272; (f) A. Tanoue, W.-J. Yoo and
S. Kobayashi, Org. Lett., 2014, 16, 2346; (g) X. Liu, S. Sun,
Z. Meng, H. Lou and L. Liu, Org. Lett., 2015, 17, 2396;
(h) H.-T. Luu, S. Wiesler, G. Frey and J. Streuff, Org. Lett.,
2015, 17, 2478; (i) C. Yan, Y. Liu and Q. Wang, Org. Lett.,
2015, 17, 5714; ( j) Y. Ji, L. Shi, M.-W. Chen, G.-S. Feng and
Y.-G. Zhou, J. Am. Chem. Soc., 2015, 137, 10496.
3 (a) D. Seebach, J.-J. Lohmann, M. A. Syfrig and
M. Yoshifuji, Tetrahedron, 1983, 39, 1963; (b) D. Seebach,
I. M. Huber and M. A. Syfrig, Helv. Chim. Acta, 1987, 70,
1357; (c) A. I. Meyers, L. M. Fuentes and Y. Kubota, Tetra-
hedron, 1984, 40, 1361; (d) A. R. Katritzky and
K. Akutagawa, Tetrahedron, 1986, 42, 2571; (e) A. I. Meyers,
D. A. Dickman and M. Boes, Tetrahedron, 1987, 43, 5095;
(f) K. Rein, M. Goicoechea-Pappas, T. V. Anklekar,
G. C. Hart, G. A. Smith and R. E. Gawley, J. Am. Chem. Soc.,
1989, 111, 2211; (g) K. S. Rein and R. E. Gawley, J. Org.
Chem., 1991, 56, 1564; (h) S. V. Kessar, R. Vohra and
N. P. Kaur, Tetrahedron Lett., 1991, 32, 3221; (i) R. E. Gawley
and P. S. Zhang, J. Org. Chem., 1996, 61, 8103;
( j) M. R. Ebden, N. S. Simpkins and D. N. A. Fox, Tetra-
hedron, 1998, 54, 12923; (k) S. Adam, X. Pannecoucke,
J. C. Combret and J. C. Quirion, J. Org. Chem., 2001, 66,
8744; (l) K. N. Singh, P. Singh, E. Sharma and Y. S. Deol,
Synthesis, 2014, 1739.
Dysoxyline 21
In the same way as the amine 18, the carbamate 20 (100 mg,
0.24 mmol) and LiAlH4 (500 mg, 1.2 mmol) gave, after purifi-
cation by column chromatography on silica, eluting with Et2O–
petrol (97.5 : 2.5), ( )-dysoxyline 21 (60 mg, 75%) as an oil;
Rf 0.12 [Petrol–Et2OH (90 : 10)]; νmax (neat)/cm−1 2935, 2780,
1
1515, 1490; H NMR (400 MHz, CDCl3) δ = 6.74–6.69 (2H, m,
CH), 6.66–6.62 (1H, m, CH), 6.58 (1H, s, CH), 6.55 (1H, s, CH),
5.92 (2H, s, OCH2O), 3.85 (3H, s, OCH3), 3.82 (3H, s, OCH3),
3.42 (1H, t, J 5, CH), 3.20–3.12 (1H, m, CH), 2.82–2.63 (4H, m,
4 × CH), 2.54–2.46 (1H, m, CH), 2.48 (3H, s, NCH3), 2.05–2.00
(2H, m, 2 × CH); 13C NMR (100 MHz, CDCl3) δ = 147.5, 147.3,
147.2, 145.4, 136.8, 129.7, 126.7, 121.0, 111.2, 110.0, 108.9,
108.1, 100.7, 62.6, 56.0, 55.8, 48.2, 42.7, 37.1, 31.3, 25.4; HRMS
(ES) Found: MH+, 356.1859. C21H26NO4 requires MH+
356.1862. Data as reported.12
4 X. Li, D. Leonori, N. S. Sheikh and I. Coldham, Chem. –
Eur. J., 2013, 19, 7724.
5 For related examples, see: (a) G. M. Coppola, J. Heterocycl.
Chem., 1991, 28, 1769; (b) J. Jiang, R. J. DeVita,
M. T. Goulet, M. J. Wyvratt, J.-L. Lo, N. Ren, J. B. Yudkovitz,
J. Cui, Y. T. Yang, K. Cheng and S. P. Rohrer, Bioorg. Med.
Chem. Lett., 2004, 14, 1795; (c) X. Li and I. Coldham, J. Am.
Chem. Soc., 2014, 136, 5551.
6 (a) D. J. Gallagher and P. Beak, J. Org. Chem., 1995, 60,
7092; (b) K. M. Bertini Gross and P. Beak, J. Am. Chem. Soc.,
2001, 123, 315; (c) I. Coldham, R. C. B. Copley,
T. F. N. Haxell and S. Howard, Org. Lett., 2001, 3, 3799;
(d) N. J. Ashweek, I. Coldham, T. F. N. Haxell and
S. Howard, Org. Biomol. Chem., 2003, 1, 1532.
Acknowledgements
We thank the University of Sheffield, the Iraqi Government,
the China Scholarship Council/Department for Business Inno-
vation & Skills (UK-China Scholarships for Excellence), and the
ERASMUS programme for support. We thank Sue Bradshaw
and Sandra van Meurs for NMR spectroscopic studies.
7 N. S. Sheikh, D. Leonori, G. Barker, J. D. Firth,
K. R. Campos, A. J. H. M. Meijer, P. O’Brien and
I. Coldham, J. Am. Chem. Soc., 2012, 134, 5300.
8 J.-F. Liégeois, J. Wouters, V. Seutin and S. Dilly, ChemMed-
Chem, 2014, 9, 737.
9 For some syntheses of crispine A, see: (a) K. Murai,
K. Matsuura, H. Aoyama and H. Fujioka, Org. Lett., 2016,
18, 1314; (b) C. Yan, Y. Liu and Q. Wang, Org. Lett., 2015,
17, 5714; (c) B. G. Das, R. Nallagonda, D. Dey and
Notes and references
1 See, for example: (a) J. Stöckigt, A. P. Antonchick, F. Wu
and H. Waldmann, Angew. Chem., Int. Ed., 2011, 50,
8538; (b) S. Kotha, D. Deodhar and P. Khedkar, Org.
Biomol. Chem., 2014, 12, 9054; (c) A. Ruiz-Olalla,
M. A. Würdemann, M. J. Wanner, S. Ingemann, J. H. van
Maarseveen and H. Hiemstra, J. Org. Chem., 2015, 80, 5125.
2 See, for example: (a) M. Chang, W. Li and X. Zhang, Angew.
Chem., Int. Ed., 2011, 50, 10679; (b) M. Ruzic, A. Pecavar,
D. Prudic, D. Kralj, C. Scriban and A. Zanotti-Gerosa, Org.
Process Res. Dev., 2012, 16, 1293; (c) F. Berhal, Z. Wu,
Z. Zhang, T. Ayad and V. Ratovelomanana-Vidal, Org. Lett.,
2012, 14, 3308; (d) W. Muramatsu, K. Nakano and C.-J. Li,
Org. Biomol. Chem., 2014, 12, 2189; (e) W. Lin, T. Cao,
W. Fan, Y. Han, J. Kuang, H. Luo, B. Miao, X. Tang, Q. Yu,
P. Ghorai, Chem.
–
Eur. J., 2015, 21, 12601;
(d) J. Selvakumar, R. S. Rao, V. Srinivasapriyan,
S. Marutheeswaran and C. R. Ramanathan, Eur. J. Org.
Chem., 2015, 2175; (e) E. Mons, M. J. Wanner, S. Ingemann,
J. H. van Maarseveen and H. Hiemstra, J. Org. Chem., 2014,
79, 7380; (f) S. Dhanasekaran, V. Bisai, R. A. Unhale,
A. Suneja and V. K. Singh, Org. Lett., 2014, 16, 6068;
This journal is © The Royal Society of Chemistry 2016
Org. Biomol. Chem.