A Regiospecific Synthesis of 1,3-Diketones via Boroxazines

References

• Brown , H. C. 1975 . Organic Synthesis via Boranes New York : J. Wiley and Sons . J. Hooz and J. Oudenes, Syn. Commun., 10, 139, 667 (1980); J. Hooz and J. N. Bridson, J. Amer. Chem. Soc., 95, 602 (1973); T. Mukaiyama, K. Inomata, and M. Muraki, J. Amer. Chem. Soc., 95, 967 (1973); S. Masamune, S. Mori, D. Van Horn, and D. W. Books, Tetrahedron Lett., 19, 1665 (1979)
   Google Scholar
• Hauser , C. R. , Swamer , F. W. and Adams , J. T. 1954 . Org. Reactions, VIII , : 59
   Google Scholar
• Hooz , J. and Linke , S. 1968 . J. Amer. Chem. Soc. , 90 : 5936 The yield-limiting step is the initial reaction of the α-diazo ketone with the hindered tri-sec-alkyl-borane, cf.
   Web of Science ®Google Scholar
• K⊘ster , R. and Fenzl , W. 1968 . Angew. Chem. Internat. Ed. , 7 : 735 Earlier studies have shown thatin situ generation of vinyloxyboranes via direct deprotonation of unsymmetric ketones by various R2BX reagents is non-regiospecific, gives poor (ca. 7%) yields of boroxazines for trialkylborane homologs higher than triethylborane, and requires thermal autoclave conditions. Aryl derivatives have been prepared by a disproportionation reaction, a process inapplicable to alkyl derivatives.;W. Fenzl and R. K⊘ster, ibid, 10, 750 (1971); W. Fenzl and R. K⊘ster, Liebigs Ann. Chem., 1322 (1975); M. J. S. Dewar and R. C. Dougherty, Tetrahedron Lett., 16, 907 (1964)
   Google Scholar
• Benderly , Dr. A. The terminal enol borane was prepared by hydride transfer from dicyclohexylborane to the corresponding α-diazoketone. Unpublished method of
   Google Scholar
• House , H. O. 1972 . Modern Synthetic Reactions, , 2nd Edition Menlo Park, Calif. : W. A. Benjamin, Inc. .
   Google Scholar