Novel Isobenzofuran Generation from Silylated Lactol Leading to Desilylated or Silylated Adducts Depending on the Choice of Metal Fluorides

Abstract

A new method of isobenzofuran generation was developed by treating silylated lactol with metal fluorides. The reactions with hard early transition metal fluorides gave de-silylated dimethyl acetylenedicarboxylate (DMAD) adduct mainly. By contrast, the silyl-retained DMAD adduct, which could be used for further transformation, was also obtained depending on the choice of metal fluorides such as lanthanoides or low valent transition metal fluor­ides.

isobenzofuran - carbonyl ylides - silylated lactol - silylated isobenzofuran adducts - metal fluorides

References

Reviews:

1a Padwa A. In Comprehensive Organic Synthesis   Vol. 4:  Trost BM. Pergamon Press; Oxford: 1991.  p.1089-1093  

1b Padwa A. Hornbuckle SF. Chem. Rev.  1991,  91:  263 

1c Ye T. Mckervey MA. Chem. Rev.  1994,  94:  1091 

1d Padwa A. Weingarten MD. Chem. Rev.  1996,  96:  223 

1e Oku A. Mori T. Sawada Y. J. Synth. Org. Chem. Jpn.  2000,  58:  934 

Reviews:

2a Haddadin MJ. Heterocycles  1978,  9:  865 

2b Friedrichsen W. Adv. Heterocyclic Chem.  1980,  26:  135 

2c Wiersum UE. Aldrichim. Acta.  1981,  14:  53 

2d Rodrigo R. Tetrahedron  1988,  44:  2093 

2e Hosomi A. J. Synth. Org. Chem., Jpn.  1998,  56:  681 

Representative methods for isobenzofuran generation:

3a Wiersum UE. Mijs WJ. J. Chem. Soc., Chem. Commun.  1972,  347 

3b Plaumann HP. Smith JG. Rodrigo R. J. Chem. Soc. Chem. Commun.  1980,  354 

3c Tobia D. Rickborn B. J. Org. Chem.  1986,  51:  3849 

3d Hamaguchi M. Ibata T. Chem. Lett.  1976,  287 

3e Hayakawa K. Yamaguchi Y. Kanematsu K. Tetrahedron Lett.  1985,  26:  2689 

(2,5) Ene cyclization:

4a Ohmura H. Smyth GD. Mikami K. J. Org. Chem.  1999,  64:  6056 

4b Ohmura H. Mikami K. Tetrahedron Lett.  2001,  42:  6859 

5 Review on l-(m,n) terminology: Mikami K. Shimizu M. Chem. Rev.  1992,  92:  1021 

6 Account on l-(m,n) terminology: Sarkar TK. J. Indian Inst. Sci.  1994,  74:  329 

Recent examples of l-(m,n) ene cyclization:

7a Loh T.-P. Hu Q.-Y. Tan K.-T. Cheng H.-S. Org. Lett.  2001,  3:  2669 

7b Okano T. Nakagawa K. Kubodera N. Ozono K. Isaka A. Osawa A. Terada M. Mikami K. Chem. Biol.  2000,  7:  173 

7c Mikami K. Osawa A. Isaka A. Sawa E. Shimizu M. Terada M. Kubodera N. Nakagawa K. Tsugawa N. Okano T. Tetrahedron Lett.  1998,  39:  3359 

7d Noguchi M. Mizukoshi T. Nishimura S. Bull. Chem. Soc. Jpn.  1997,  70:  2201 

Reviews on sequential reactions:

8a Nakai T. Mikami K. Kagaku no Ryoiki  1982,  36:  661 ; Chem. Abstr. 1982, 96, 16001

8b Ziegler FE. In Comprehensive Organic Synthesis   Vol. 5:  Trost BM. Fleming I. Pergamon Press; Oxford: 1991.  p.875 

8c Ho T.-L. Tandem Organic Reactions   Wiley; New York: 1992. 

8d Tietze LF. Beifuss U. Angew. Chem., Int. Ed. Engl.  1993,  32:  131 

8e Special issue on frontiers in organic reaction sequence: Wender PA. Chem. Rev.  1996,  96:  1 

For recent reviews on transition metal fluorides, see

9a Murphy EF. Murugavel R. Roesky HW. Chem. Rev.  1997,  97:  3425 ; and references therein

9b Doherty NM. Hoffman NW. Chem. Rev.  1991,  91:  553 

9c Pagenkopf BL. Carreira EC. Chem.-Eur. J.  1999,  5:  3437 

Spectral data of adduct 2a and 2c were agreement with the literature data.

10a For adduct 2a see: Sambaiah T. Huang D.-J. Cheng C.-H. J. Chem. Soc., Perkin Trans. 1  2000,  195 

10b For adduct 2c see: Crump SL. Rickborn B. J. Org. Chem.  1984,  49:  304 

TiF₄ Complex:

11a Gauthier DR. Carreira EM. Angew. Chem., Int. Ed. Engl.  1996,  35:  2363 

11b Duthaler RO. Hafner A. Angew. Chem., Int. Ed. Engl.  1997,  36:  43