A New Modified “Montanari Oxidation Process” by Means of Chlorine Dissolved in the Reaction Solvent as Oxidant and TEMPO as Catalyst: Oxidation of 3- S- Quinuclidinol to 3-Quinuclidinone
2002; American Chemical Society; Volume: 6; Issue: 2 Linguagem: Inglês
10.1021/op010096x
ISSN1520-586X
AutoresHans‐René Bjørsvik, Lucia Liguori, Francesca Costantino, Francesco Minisci,
Tópico(s)Alkaloids: synthesis and pharmacology
ResumoResults from a process improvement project for preparation of 3-R-quinuclidinol, a highly valuable intermediate for several muscarine-active compounds are described. The studied process was based on the kinetic resolution of racemic 3-quinuclidinol and thus involved a large side-stream production. Our outline for process improvement is based on that this side stream can be recycled by a two-step sequence of oxidation and reduction processes. Findings concerning the conversion of 3-S-quinuclidinol into 3-quinuclidinone by using an improved oxidation process based on TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl radical) and molecular chlorine are discussed in detail. The developed oxidation procedure affords nearly quantitatively yield in the conversion of 3-S-quinuclidinol into 3-quinuclidinone.
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