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DOI: 10.1055/s-2002-35994
Synthetic Applications of 3,4-Dihalo-2(5H)-furanones: A Formal Total Synthesis of Nostoclides I and II
Publication History
Publication Date:
06 December 2002 (online)
Abstract
3-Benzyl-4-isopropyl-2(5H)-furanone, which is a precursor to two naturally-occurring cytotoxic (Z)-5-ylidene-2(5H)-furanone derivatives, has been conveniently prepared from 3,4-dibromo-2(5H)-furanone by a three-step procedure involving two Pd-catalyzed cross-coupling reactions and a Rh(I)-catalyzed hydrogenation.
Key words
2(5H)-furanones - cross-coupling - regioselectivity - Stille reaction - benzylation
- 1
Rossi R.Bellina F.Raugei E. Synlett 2000, 1749 - 2
Bellina F.Anselmi C.Rossi R. Tetrahedron Lett. 2002, 43: 2023 - 3
Bellina F.Anselmi C.Viel S.Mannina L.Rossi R. Tetrahedron 2001, 57: 9997 - 4
Bellina F.Anselmi C.Rossi R. Tetrahedron Lett. 2001, 42: 3851 - 5
Ortega MJ.Zubía E.Ocaña JM.Naranjo S.Salvá J. Tetrahedron 2000, 56: 3963 - 6
Evidente A.Randazzo G.Ballio A. J. Nat. Prod. 1986, 49: 593 - For reviews on the synthesis of stereodefined 5-ylidene-2(5H)-furanones, see:
-
7a
Negishi E.-I.Kotora M. Tetrahedron 1997, 53: 6707 -
7b
Brückner R. Curr. Org. Chem. 2001, 5: 679 -
7c
Brückner R. Chem. Commun. 2001, 141 -
7d
Rossi R.Bellina F. Targets in Heterocyclic Systems: Chemistry and Properties 2002, 5: 169 - 8
Bellina F.Rossi R. ; Abstracts from Transmediterranean Colloquium on Heterocyclic Chemistry; Bari Italy June 20-24: 2002. - 9
Yang X.Shimizu Y.Steiner JR.Clardy J. Tetrahedron Lett. 1993, 34: 761 - 10
Boukouvalas J.Maltais F.Lachance N. Tetrahedron Lett. 1994, 35: 7897 - 11 This compound was prepared according
to a procedure reported in the literature:
Snyder HR.Kuch JA.Johnson JR. J. Am. Chem. Soc. 1938, 60: 105 - 12
Ngwe H.Nakayama E.Higashi T.Kinoshita H.Inomata K. Chem. Lett. 1995, 713 - For previous examples of Pd-catalyzed reactions between Csp 2-hybridized halides and benzylzinc halides, see:
-
15a
Negishi E.-i.Tan Z.Liou S.-Y.Liao B. Tetrahedron 2000, 56: 10197 -
15b
Gundersen L.-L.Langli G.Rise F. Tetrahedron Lett. 1995, 36: 1945 -
15c
Gundersen L.-L.Bakkestuen AK.Aasen J.Overas H.Rise F. Tetrahedron 1994, 50: 9743 -
15d
Moriya T.Miyaura N.Suzuki A. Chem. Lett. 1993, 1429 -
15e
Negishi E.-i.King AO.Okukado N. J. Org. Chem. 1977, 42: 1821 -
17a
Chuang C.Gallucci JC.Hart DJ.Hoffmann C. J. Org. Chem. 1988, 53: 3218 -
17b
Labadie JW.Tueting D.Stille JK. J. Org. Chem. 1983, 48: 4634 - 18
Desponds O.Schlosser M. J. Organomet. Chem. 1991, 409: 93
References
It should be noted that when we attempted to prepare 8a by hydrogenation of 18 in toluene at r.t. in the presence of 10 mol% Pd on BaSO4, the reaction provided significant amounts of a compound which had a MS spectrum corresponding to that of 4-isopropyl-2(5H)-furanone.
14The catalyst precursor constiting of Pd2(dba)3 (2.5 mol%)/(o-Tol)3P (10 mol%) gave a similar yield, while the use of Pd2(dba)3 (2.5 mol%)/Ph3As (10 mol%) or Pd(PPh3)4 (5 mol%) as catalyst precursors gave less satisfactory results.
16It should be noted that the crude
product, derived from the Pd-catalyzed reaction of 8a with 20, contained compound 14 and
significant amounts of 1,2-diphenylethane (22)
and a compound which had a MS spectrum in agreement with that of
3,5-dibenzyl-4-isopropyl-2(5H)-furanone.
The
use of PdCl2[(o-Tol)3P]2 (5
mol%)/CuI (10 mol%), Pd2(dba)3 (2.5
mol%)/Ph3As (10 mol%)/CuI
(10 mol%) or Pd2(dba)3 (2.5 mol%)/t-Bu3P (10 mol%)/CuI
(10 mol%) as catalyst precursors in NMP at 85 °C
gave less satisfactory results, while employing Pd2(dba)3 (2.5
mol%)/t-Bu3P
(10 mol%) as a catalyst precursor in dioxane at reflux
and in the presence of 3 equiv of KF no product was obtained.