- The rearrangement of 2,3-epoxysulfonates and its application to natural products syntheses: Formal synthesis of (-)-aphanorphine and total syntheses of (-)-α-herbertenol and (-)-herbertenediol
-
The Lewis acid treatment of 2,3-epoxysulfonates with 2,3-dialkyl substituents or 2-alkyl-3-aryl substituents produced the rearrangement products via C3-cleavage of the oxirane ring in high yields. On the other hand, 2-aryl-3-alkyl-2,3-epoxysulfonates produced the products via C2-cleavage of the oxirane ring. The sulfonyloxy groups of the α-sulfonyloxy ketones, having a chiral benzylic quaternary carbon center obtained by the rearrangement of 2-alkyl-3-aryl-2,3-epoxysulfonates, were reductively eliminated to give the ketones with a chiral benzylic quaternary carbon center. The method was applied to the formal synthesis of (-)-aphanorphine and total syntheses of (-)-α-herbertenol and (-)-herbertenediol.
- Kita, Yasuyuki,Futamura, Junko,Ohba, Yusuke,Sawama, Yoshinari,Ganesh, Jnaneshwara K.,Fujioka, Hiromichi
-
p. 5917 - 5924
(2007/10/03)
-
- Concise asymmetric synthesis of (-)-herbertenediol
-
The rearrangement of the optically active 3-aryl-2-methyl-2,3-epoxy tosylate (>98% ee) afforded the α-keto tosylate with a chiral quaternary carbon center and without loss of chirality. Reductive removal of the tosyloxy group gave the keto compound with a chiral quaternary carbon center, which was converted to (-)-herbertenediol (>98% ee).
- Kita, Yasuyuki,Futamura, Junko,Ohba, Yusuke,Sawama, Yoshinari,Ganesh, Jnaneshuwara K.,Fujioka, Hiromichi
-
p. 411 - 413
(2007/10/03)
-
- New route to herbertanes via a Suzuki cross-coupling reaction: Synthesis of herbertenediol
-
The synthesis of herbertenediol, a relevant member of the herbertane-type sesquiterpene family, is described. The synthesis is based on a new general approach to this group of sesquiterpenes where the herbertane skeleton is constructed using a Suzuki cross-coupling reaction and a [2,3]-sigmatropic Still-Wittig rearrangement as key synthetic steps.
- Abad, Antonio,Agulló, Consuelo,Cu?at, Ana C,Jiménez, Diego,Perni, Remedios H
-
p. 9727 - 9735
(2007/10/03)
-