Hydration with mercuric acetate and the reduction with 9-BBN-H of 2-(1-alkenyl)-4,6-dimethyl-s-triazines.
Oxymercuration-demercuration of a double bond in conjugation with the 4,6-dimethyl-s-triazin-2-yl substituent as in alkenes 1a,b gave anti-Markovnikov regioselectivity, which is explained by the electron-withdrawing nature of the triazinyl substituent. However, hydroboration of the conjugated alkenes with 9-BBN-H gave the corresponding alkanes 5a-c under normal workup conditions with or without oxidation. With time and without workup the hydroboration of 1b gave spectral evidence for the formation of intermediates 9-13 resulting from the migration of the 9-BBN moiety from the alpha-carbon to a ring nitrogen with concurrent formation of an exocyclic double bond to an alpha-carbon of the ring. Hydrolysis of the intermediates gave 5a-c. A possible mechanism involving successive allylic rearrangements is presented.
Nyquist
H LeRoy
HL
Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA. leroy.nyquist@csun.edu
Beeloo
Edward A
EA
Hurlbut
Lydia S
LS
Watson-Clark
Rachel
R
Harwell
David E
DE