Kettenverlängerung funktionalisierter Alkanone durch Umlagerung
1981; Wiley; Volume: 64; Issue: 6 Linguagem: Inglês
10.1002/hlca.19810640619
ISSN1522-2675
AutoresA. Lorenzi-Riatsch, Y. NAKASHITA, Manfred Hesse,
Tópico(s)Chemical Synthesis and Reactions
ResumoChain Expansion of Functionalized Alkanones by Rearrangement Reactions In analogy to the transamidation reactions which were published earlier a method is described to prolong aliphatic C‐chains by two or four C‐atoms. 1,3‐Diketones or 2‐nitro alkanones which are monosubstituted at C(2) are condensed with e.g. methyl vinyl ketone. The reaction product is transformed to its chain‐prolonged isomer in the presence of strong base via a 4‐ or 6‐membered intermediate. The most effective reagent for the Michael reaction is methyl 3‐oxo‐4‐pentenoate ( 20 ). In this case it was possible to convert 3‐nitro‐2‐butanone ( 21 ) to methyl 2‐acetyl‐6‐nitro‐3‐oxoheptanoate ( 26 ) in 82% yield.
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