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1
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33845238277
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For a review of methods for making THF rings, see
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For a review of methods for making THF rings, see: J. P. Wolfe, M. B. Hay, Tetrahedron 2007, 63, 261.
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Wolfe, J.P.1
Hay, M.B.2
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3
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23044503924
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Angew. Chem. Int. Ed. 2005, 44, 4766-4768.
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Angew. Chem. Int. Ed
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5
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34548682314
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For a general review of oxidative cyclization by metal oxo species, see
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For a general review of oxidative cyclization by metal oxo species, see: V. Piccialli, Synthesis 2007, 2585.
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Synthesis
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Piccialli, V.1
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8
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0033117665
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b) K. Nagasawa, N. Hori, H. Koshino, T. Nakata, Heterocycles 1999, 50, 919;
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Heterocycles
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Nagasawa, K.1
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Nakata, T.4
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9
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0034211027
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c) S. Takahashi, K. Fujisawa, N. Sakairi, T. Nakata, Heterocycles 2000, 53, 1361;
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Heterocycles
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Takahashi, S.1
Fujisawa, K.2
Sakairi, N.3
Nakata, T.4
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10
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0034622878
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d) N. Hayashi, H. Noguchi, S. Tsuboi, Tetrahedron 2000, 56, 7123;
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Tetrahedron
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Hayashi, N.1
Noguchi, H.2
Tsuboi, S.3
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11
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2242470784
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for ring expansion reactions of secondary mesylates derived from oxidative cyclization, see
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e) for ring expansion reactions of secondary mesylates derived from oxidative cyclization, see: R. C. D. Brown, P. J. Kocienski, Synlett 1994, 415.
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Synlett
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Brown, R.C.D.1
Kocienski, P.J.2
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12
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53549098439
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The analogue of compound 5, which is diastereomeric at the OMs center, returned starting material under the reaction conditions. This stereoelectronic effect can be considered to be further evidence for a concerted hydride shift/OMs displacement, because the reactive conformation (C-H and C-OMs antiperiplanar) suffers from undue steric hinderance between the sidechain and the THF ring: this strain is reduced with its diastereoisomer 5.
-
The analogue of compound 5, which is diastereomeric at the OMs center, returned starting material under the reaction conditions. This stereoelectronic effect can be considered to be further evidence for a concerted hydride shift/OMs displacement, because the reactive conformation (C-H and C-OMs antiperiplanar) suffers from undue steric hinderance between the sidechain and the THF ring: this strain is reduced with its diastereoisomer 5.
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-
-
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13
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53549105414
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We do not assume concomitant attack of acetate anion and loss of hydride from the silicon. Removal of the silyl group that is generated by this mechanism, as shown in Scheme 3, is straightforward using tetra-n-butylammonium fluoride (TBAF, For related directed ionic hydrogenation reactions, see: a) S. Anwar, G. Bradley, A. P. Davis, J. Chem. Soc. Perkin Trans. 1 1991, 1381;
-
We do not assume concomitant attack of acetate anion and loss of hydride from the silicon. Removal of the silyl group that is generated by this mechanism, as shown in Scheme 3, is straightforward using tetra-n-butylammonium fluoride (TBAF). For related directed ionic hydrogenation reactions, see: a) S. Anwar, G. Bradley, A. P. Davis, J. Chem. Soc. Perkin Trans. 1 1991, 1381;
-
-
-
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14
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0027452078
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b) R. J. P. Corriu, G. F. Lanneau, Z. Yu, Tetrahedron 1993, 49, 9019;
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Tetrahedron
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Corriu, R.J.P.1
Lanneau, G.F.2
Yu, Z.3
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15
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85022401078
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c) S. W. McCombie, C. Ortiz, B. Cox, A. K. Ganguly, Synlett 1993, 541.
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McCombie, S.W.1
Ortiz, C.2
Cox, B.3
Ganguly, A.K.4
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18
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0033616106
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3SiH) onto oxonium ions such as A gives predominantly the cis diastereoisomer, presumably for steric reasons; see also Scheme 6. For the influence that substituents within the THF ring can have on oxonium ion trapping, see: a) C. H. Larsen, B. H. Ridgway, J. T. Shaw, K. A. Woerpel, J. Am. Chem. Soc. 1999, 121, 12208;
-
3SiH) onto oxonium ions such as A gives predominantly the cis diastereoisomer, presumably for steric reasons; see also Scheme 6. For the influence that substituents within the THF ring can have on oxonium ion trapping, see: a) C. H. Larsen, B. H. Ridgway, J. T. Shaw, K. A. Woerpel, J. Am. Chem. Soc. 1999, 121, 12208;
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-
-
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19
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53549132679
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b) D. A. Evans, L. Kværnø, J. A. Mulder, B. Raymer, T. B. Dunn, A. Beauchemin, E. J. Olhava, M. Juhl, K. Kagechika, Angew. Chem. 2007, 119, 4777-4781;
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Angew. Chem
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Evans, D.A.1
Kværnø, L.2
Mulder, J.A.3
Raymer, B.4
Dunn, T.B.5
Beauchemin, A.6
Olhava, E.J.7
Juhl, M.8
Kagechika, K.9
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20
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34347245264
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Angew. Chem. Int. Ed. 2007, 46, 4693-4697.
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(2007)
Angew. Chem. Int. Ed
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