122052-53-3Relevant articles and documents
The total synthesis of (+)-petasin and (+)-isopetasin
Witschel, Matthias C.,Bestmann, Hans Jürgen
, p. 107 - 112 (2007/10/03)
Petasin 1 and isopetasin 2, anti-inflammatory and analgesic components of the butterbur (Petasites hybridus), were prepared for the first time in a short and enantioselective synthesis. The key steps were a Michael addition/alkylation (7 → 8), an enamine alkylation to give 9 and a cyclization with N-phenyliminoketenylidenetriphenylphosphorane 11 (10 → 15).