The Synthesis of Viridamine, A Penicillium Viridicatum Mycotoxin

References

• Holzapfel , C. W. and Marsli , J. J. 1977 . S. Afr. J. Chem. , 30 : 197
   Google Scholar
• Dippenaar , A. , Holzapfel , C. W. and Boeyens , J. C. A. S. 1977 . Afr. J. Chem. , 30 : 161
   Google Scholar
• Dziuron , P. and Schunack , W. 1973 . Arch. Pharm. , 306 : 347 For example reaction of alkylimino ethers with α-hydroxy ketones and ammonia under pressure
   Web of Science ®Google Scholar
• Iddon , B. 1985 . Heterocycles , 23 : 417 For a review on the metailation and reaction of imidazoles, see
   Web of Science ®Google Scholar
• Totter , J. R. and Darby , W. J. 1967 . Organic Synthesis Collective , Edited by: Horning , E. C. Vol. III , 460 New York : John Wiley and Sons .
   Google Scholar
• Manoharan , T. S. and Brown , R. S. 1988 . J. Org. Chem. , 53 : 1107 and cited references.
   Web of Science ®Google Scholar
• Attempted alkylation of the 1-benzyl-4-[(trimethylsilyloxy)methyl]-imidazole yielded a mixture of imidazoles alkylated benzylically and/or at position-2 (see ref. 20). 4-[(Trimethylsilyloxy)methyl]-1-(toluenesulphonyl)imidazole yielded complex mixtures. O,1-bis(tetrahydropyran-2-yl)-4-(hydroxyinethyl)imidazole was essentially unreactive but yielded small amounts of byproduct in which the desired alkylated product was further alkylated at the allylic 1′-position. A further disadvantage in the use of tetrahydropyranyl protecting groups is the severe conditions required for O-deprotection.
   Google Scholar
• The O-trimethylsilyl analogue gives lower yields (63%) presumably due to slight n-butyllithiuni induced desilylation.
   Google Scholar
• Corey , E. J. and Semmelhack , M. F. 1967 . J. Amer. Chem. Soc. , 89 : 2755 For an overview of the synthetic applicability of allylnickel(I) complexes see Billington, D. C., Chem. Soc. Rev., 1985, 14 , 93.
   Web of Science ®Google Scholar
• Holzapfel , C. W. , Gildenhuys , P. J. and Afr , S. 1977 . J. Chem. , 30 : 125 and Plieninger, H. and Sirowej, H., Chem. Ber., 1971, 104 , 2027.
   Web of Science ®Google Scholar
• Kirk , K. L. 1978 . J. Org. Chem. , 43 : 4381
   Web of Science ®Google Scholar
• Hegedus , L. S. and Miller , L. L. 1975 . J. Amer. Chem. Soc. , 97 : 459
   Web of Science ®Google Scholar
• Eschenmoser , A. 1970 . Chem. Soc. Quart. Rev. , 24 : 366 Roth, M., Dubs, P., Götschi, E. and Eschenmoser, A., Helv. Chim. Acta, 1971, 54 , 710 and Götschi, E., Hunkeler, W., Wild, H.-J., Schneider, P., Fuhrer, W., Gleason, J, and Eschenmoser, A., Angew. Chem. (Int. Ed.), 1973, 12 , 910.
   Google Scholar
• Vorbrüggen , H. and Krolikiewicz , K. 1976 . Angew. Chem. (Int. Ed.) , 15 : 689
   PubMed Web of Science ®Google Scholar
• Jones , R. G. 1949 . J. Amer. Chem. Soc. , 71 : 644
   PubMed Web of Science ®Google Scholar
• Bond , R. F. and Holzapfel , C. W. unpublished results.
   Google Scholar
• Breitholle , E. G. and Stammer , C. H. 1976 . J. Org. Chem. , 41 : 1344
   PubMed Web of Science ®Google Scholar
• Better yields are obtained on prior acetylation of cyclo-glycyl-L-valyl, which is routinely prepared (See ref. 22).
   Google Scholar
• Use of a stronger base such as DBN or raising the reaction temperature from 100 to 120°C resulted in a dramatic loss of product yield to the acetic anhydride-formylimidazole condensate.
   Google Scholar
• Schöllkopf , U. , Gerhart , F. , Schroder , R. and Hoppe , D. 1972 . Liebigs Ann. Chem. , 766 : 116
   Google Scholar
• Tang , C. C. , Davalian , D. , Huang , P. and Breslow , R. 1978 . J. Amer. Chem. Soc. , 100 : 3918 and Chadwick, D. J. and Ngochindo, R. I., J. Chem. Soc., Perkin Trans. I, 1984, 481.
   Web of Science ®Google Scholar
• Nitecki , D. E. , Halpern , B. and Westley , J. W. 1968 . J. Org. Chem. , 33 : 864
   PubMed Web of Science ®Google Scholar