(S)-beta-Bisabolene, (S)-1, was synthetized by a synthetic route in which (S)-4-methyl-3-cyclohexene carboxylic acid, (S)-10, which was the key intermediate, was prepared via a highly diastereoselective TiCl4-catalyzed Diels-Alder reaction between isoprene and the acrylate of commercial (R)-pantolactone, followed by hydrolysis. Compound (S)-10 was then converted into ketone (S)-13 using two different procedures, The best one of these, as regards the degree of stereospecificity, involved the reaction of (S)-10 with 2 equiv of 4-methyl-3-penten-1-yllithium, 14, in the presence of CeCl3, and gave (S)-13 having ca. 84% ee. The Zr-promoted methylenation of this ketone afforded highly enantiomerically enriched (S)-1.
|Autori:||Argenti, L; Bellina, Fabio; Carpita, Adriano; Rossi, Renzo|
|Titolo:||ASYMMETRIC-SYNTHESIS OF HIGHLY ENANTIOMERICALLY ENRICHED (S)(-)-BETA-BISABOLENE|
|Anno del prodotto:||1995|
|Digital Object Identifier (DOI):||10.1080/00397919508011421|
|Appare nelle tipologie:||1.1 Articolo in rivista|