S. Ghosh et al. / Tetrahedron Letters 46 (2005) 5479–5481
5481
713–734; (e) Ishigami, K.; Kitahara, T. Heterocycles 2004,
63, 785–790; (f) Chavan, S. P.; Praveen, C. Tetrahedron
Lett. 2003, 44, 2873–2875; (g) Davoli, P.; Fava, R.;
Morandi, S.; Spaggiari, A.; Parti, F. Tetrahedron 2005,
61, 4427–4436; (h) Kumar, P.; Naidu, S. V. J. Org. Chem.
2005, 70, 4207–4210.
10:1 E:Z mixture of macrocyclic lactones, from which
the (E)-isomer 20 was isolated by silica gel column chro-
matography. Global deprotection of E-20 gave micro-
carpalide 1 (Scheme 4).2b The spectroscopic and
analytical data of compound 1 and other compounds
were in good agreement with literature data.2a,b,8
3. (a) Deiters, A.; Martin, S. F. Chem. Rev. 2004, 104, 2199–
2238; (b) Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res.
In conclusion, we have achieved a convergent total syn-
thesis of (ꢀ)-microcarpalide from the commercially
available, cheap starting material D-mannitol. The prep-
aration analogues and a study of their biological activi-
ties are currently under progress.
2001, 34, 18–19; (c) Furstner, A. Angew. Chem., Int. Ed.
¨
2000, 39, 3012–3043.
4. Mulzer, J.; Angermann, A.; Munch, W. Liebigs Ann. Chem.
¨
1986, 825–838.
5. Lipshutz, B. H.; Sengupta, S. Org. React. 1992, 41, 135–
631.
6. Chakraborty, T. K.; Ghosh, S.; Rao, M. H. V. R.; Kunwar,
A. C.; Cho, H.; Ghosh, A. K. Tetrahedron Lett. 2000, 41,
10121–10125.
Acknowledgements
7. Garegg, P. G.; Samuclson, B. Synthesis 1979, 813–
814.
8. Selected physical data of E-20. Rf = 0.5 (silica, 20% EtOAc
We are thankful to CSIR (R.V.R.) and UGC (J.S.),
New Delhi for research fellowships. We are also thank-
ful to Dr. T. K. Chakraborty, Dr. A. C. Kunwar and the
Director, IICT for their support and encouragement.
27
1
in petroleum ether); ½aꢁD ꢀ35.5 (c 1.2, CHCl3); H NMR
data (CDCl3, 500 MHz): d 7.28–7.35 (m, 10H), 5.64–5.73
(m, 1H), 5.63 (dd, J = 15.7, 2.0 Hz, 1H), 5.15 (dt, J = 9.5,
4.6 Hz, 1H), 4.77–4.81 (m, 2H), 4.65 (d, J = 12.1 Hz, 1H),
4.54 (d, J = 11.9Hz, 1H), 4.47 (d, 1H, J = 12.8 Hz, 1H),
4.46 (d, J = 11.5 Hz, 1H), 4.07 (d, J = 4.1 Hz, 1H), 3.66–
3.78 (m, 4H), 3.53–3.56 (m, 2H), 3.38 (s, 3H), 2.61 (dd,
J = 14.3, 9.4 Hz, 1H), 2.22–2.32 (m, 2H), 2.11–2.20 (m, 1H),
1.96–2.04 (m, 1H), 1.54–1.59 (m, 3H), 1.26–1.32 (m, 8H),
0.88 (t, J = 6.8 Hz, 3H); 13C NMR (CDCl3, 75 MHz): d
175.2, 138.7, 138.4, 131.6, 128.3, 128.2, 127.6, 127.5, 127.2,
126.4, 95.3, 78.1, 71.7, 71.5, 71.3, 67.4, 59.0, 36.0, 31.7, 31.1,
29.4, 25.0, 22.5, 14.0; HRMS (ESI) calcd for C34H48O7Na
[M+Na]+ 591.3297. Found 591.3307.
References and notes
1. Ratnayake, A. S.; Yoshida, W. Y.; Mooberry, S. L.;
Hemscheidt, T. Org. Lett. 2001, 3, 3479–3481.
2. (a) Murga, J.; Falmoir, E.; Garcia-Fortanet, J.; Carda, M.;
Marco, J. A. Org. Lett. 2002, 4, 3447–3449; (b) Gurjar, M.
K.; Nagaprasad, R.; Ramana, C. V. Tetrahedron Lett.
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gnetti, L.; Parti, F. Org. Biomol. Chem. 2004, 2, 38–47; (d)
Banwell, M. G.; Loong, D. T. J. Heterocycles 2004, 62,