Selective Reduction of the Exomethylene Group of α-Methylene γ- or δ-Lactones with CdCl2–Mg–MeOH–H2O‡
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Asish K. Bhattacharya, Dharam C. Jain and Ram P. Sharma
Abstract
The strained exomethylene group of the α-methylene γ- or δ-lactone moiety in sesquiterpenoids can be selectively reduced with the CdCl2–Mg–MeOH–H2O reagent system.
References
C. Sarangi, A. Nayak, B. Nanda, N. B. Das and R. P. Sharma, Tetrahedron Lett., 1995, 36, 7119 CrossRefCAS.
A. K. Bhattacharya, D. C. Jain, R. P. Sharma, R. Roy and A. T. McPhail, Tetrahedron, 1997, 53, 14975 CrossRefCAS . Arteannuin B 1 is
the biogenetic precursor of artemisinin, a potent antimalarial
drug; e.g. S. S. Zaman and R. P. Sharma, Heterocycles, 1991, 32, 1593 Search PubMed.
For preparatiaon of compounds 4 and 15, see A. K. Pathak, D. C. Jain, R. S. Bhakuni, P. K. Choudhuri and R. P. Sharma, J. Nat. Prod., 1994, 57, 1708 Search PubMed.
C. R. Narayanan and N. K. Venkatasubramanian, J. Org. Chem., 1968, 33, 3156 CrossRefCAS.
Acetate 12 was prepared from compound 4 using
BF3–Ac2O.
For comparison with Ni2B reduction, see
(a) C. A. Brown, Chem. Commun, 1969, 952 RSC and references cited therein;
(b) C. A. Brown and V. K. Akuja, J. Org. Chem., 1973, 38, 2226 CrossRefCAS;
(c) C. A. Brown, J. Org. Chem., 1970, 35, 1900 CrossRefCAS.
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