Formation of Δ⁴-6-Keto Isomer in the Synthesis of Δ²-6-Keto Steroids Used as Intermediates in the Synthesis of Brassinolide and Analogous Plant Growth Stimulators

References

• Thompson , M. J. , Mandava , N. B. , Meudt , W. J. , Lusby , W. R. and Spaulding , D. W. 1981 . Steroids , 38. : 567
   PubMed Web of Science ®Google Scholar
• Wada , K. and Maruma , S. 1981 . Agric. Biol. Chem. , 45 : 2579
   Web of Science ®Google Scholar
• Takatsuto , S. , Yazawa , N. , Ishiguro , M. , Morisaki , M. and Ikekawa , N. 1984 . J. Chem. Soc. Perkin. Trans 1 , 2 : 139
   Google Scholar
• Anastasia , M. , Ciuffreda , P. and Fiecchi , A. 1983 . J. Chem. Soc. Perkin Trans 1 , 2 : 379
   Google Scholar
• Mori , K. , Sakakibara , M. , Ichikawa , Y. , Ueda , H. , Okada , K. , Umemura , T. , Yabuta , G. , Kuwahara , S. , Kondo , M. , Minobe , M. and Sogabe , A. 1982 . Tetrahedron , 38 : 2099
   Web of Science ®Google Scholar
• Sakakibara , M. and Mori , K. 1983 . Agric. Biol. Chem. , 47 : 1405 ibid 1407 and relevant references cited.
   Web of Science ®Google Scholar
• Mori , K. Eur. Pat. Appl. EP . 40, 517 . 1981 . JP Appl 80/65, 602, 16 May (1980); C. A. 96: 181507W. 25 Nov.
   Google Scholar
• Barton , D. H. R. , Lusinchi , X. , Magdzinski , L. and Ramirez , J. S. 1984 . J. Chem. Soc., Chem. Commun. , 18 : 1236
   Google Scholar
• p-Toluenesulphonic acid was dried by azeotropic removal of water with dry benzene. To the benzene solution ten times by weight silica gel (column grade) was added and the solvent removed under low pressure at 50–60° and finally under high vacuum.
   Google Scholar
• Barton , D. H. R. , Feakins , P. G. , Poyser , J. P. and Sammes , P. G. J. Chem. Soc. (c) , 1970 1584
   Google Scholar