Die Wohl‐Ziegler ‐Bromierung von Tiglin‐ und Angelika‐säureestern
1970; Wiley; Volume: 53; Issue: 2 Linguagem: Inglês
10.1002/hlca.19700530221
ISSN1522-2675
AutoresAchim Löffler, Richard J. Pratt, H. Rüesch, Aǹdré S. Dreiding,
Tópico(s)Organometallic Compounds Synthesis and Characterization
ResumoAbstract The Wohl ‐ Ziegler bromination (with N‐bromo‐succinimide = NBS) of methyl tiglate ( 1b ) gave a 2:1 mixture of methyl γ‐bromotiglate ( 3b ) and methyl β′‐bromotiglate ( 5b ). This ratio of γ‐ to β′‐bromination was unaffected by changes of solvent, catalyst or size of the ester alkoxy group. The same products were obtained from the NBS treatment of methyl angelate ( 2b ). This NBS‐bromination appears to be thermodynamically controlled, since both angelic and tiglic acid as well as their methyl esters were brought into equilibrium ( 1 ⇆ 2 = > 9:1) with catalytic amounts of NBS.
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