Synthesis of (tetrahydrofuranyl)tetrahydrofurans via radical cyclization of bis(β-alkoxyacrylates)
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Eun Lee, Ho Young Song and Hee Jo Kim
Abstract
Radical cyclizations of bis(β-alkoxyacrylates) obtained from (3R,4R)- and meso-1,6-dibromohexane-3,4-diol proceed to form a C2-symmetric and a meso (tetrahydrofuranyl)tetrahydrofuran derivative.
References
(a) E. Lee, J. S. Tae, C. Lee and C. M. Park, Tetrahedron Lett., 1993, 34, 4831 CrossRefCAS;
(b) E. Lee, J. S. Tae, Y. H. Chong, Y. C. Park, M. Yun and S. Kim, Tetrahedron Lett., 1994, 35, 129 CrossRefCAS;
(c) E. Lee and C. M. Park, J. Chem. Soc., Chem. Commun., 1994, 293 RSC;
(d) E. Lee, J.-w. Jeong and Y. Yu, Tetrahedron Lett., 1997, 38, 7765 CrossRefCAS;
(e) E. Lee, C. M. Park and J. S. Yun, J. Am. Chem. Soc., 1995, 117, 8017 CrossRefCAS;
(f) E. Lee, S.-K. Yoo, Y.-S. Cho, H.-S. Cheon and Y. H. Chong, Tetrahedron Lett., 1997, 38, 7757 CrossRefCAS.
In this case, a small amount of the minor product
4 was also obtained.
E. Lee, S.-K. Yoo, H. Choo and H. Y. Song, Tetrahedron Lett., 1998, 39, 317 CrossRefCAS.
A trace amount of a minor (presumably epimeric) product was
obtained.
Sharpless asymmetric dihydroxylation of trans-1,6-dibromohex-3-ene,
obtained from trans-hex-3-ene-1,6-diol via mesylation
and bromide substitution, provided 74% yield of (3R,4R)-1,6-dibromohexane-3,4-diol
in high enantiomeric excess (>98%). Reaction of this diol with ethyl propiolate was a little sluggish, and
gave 40% yield of the corresponding bis(β-alkoxyacrylate). Radical
cyclization produced ethyl ester analogues of 16 and 17 in 72% and
6% yield, respectively.
(a) U. Koert, Synthesis, 1995, 115 CrossRefCAS;
(b) Many of the more recent references on the synthesis of Annonaceous acetogenins may be found in A. Sinha, S. C. Sinha, S. C. Sinha and E. Keinan, J. Org. Chem., 1999, 64, 2381 Search PubMed.
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