Synthesis of (−)-Morphine: Application of Sequential Claisen/Claisen Rearrangement of an Allylic Vicinal Diol

Autor: Ryosuke Saito, Shohei Miwa, Hiroki Tanimoto, Takaaki Sato, Noritaka Chida, Masato Ichiki
Rok vydání: 2012
Předmět:
Zdroj: Chemistry - A European Journal. 19:264-269
ISSN: 0947-6539
Popis: A detailed exploration of the synthesis of (-)-morphine based on sequential [3,3]-sigmatropic rearrangements is described. The sequential Claisen/Claisen rearrangements of an allylic vicinal diol resulted in the stereoselective formation of the two contiguous carbon centers, including a sterically encumbered quaternary carbon, in a single operation. The two ethyl esters generated in this reaction were successfully differentiated during a subsequent Friedel-Crafts-type cyclization. The (-)-morphine double bond was introduced at a late stage in our first-generation synthesis, but was formed at an earlier stage in the second-generation synthesis, resulting in a more efficient route to the end product.
Databáze: OpenAIRE