Silicon guided rearrangement of epoxydecalines to spirocyclic compounds. Synthesis of gleenol and axenol from carvone
摘要:
The synthesis of the spirocyclic sesquiterpenes (-)-gleenol and (-)-axenol in enantiomerically pure form has been achieved starting from R-(-)-carvone. The key step is the silicon guided acid-promoted rearrangement of a 9-trimethylsilyl-5,6-epoxy-noreudesmane prepared from 3-tiimethylsilyldihydrocarvone in several steps involving Robinson annulation, enone deconjugation and epoxidation. Acid treatment of the epoxy-noreudesmane gave a norspiroaxane as the main product, which was used as intermediate for the synthesis of two naturally occurring sesquiterpenes gleenol and axenol. (c) 2005 Elsevier Ltd. All rights reserved.
Total Synthesis of (.+-.)-Gleenol and (.+-.)-Axenol via a Functionalized Spiro[4.5]decane
作者:Atsuo Nakazaki、Tomohiro Era、Susumu Kobayashi
DOI:10.1248/cpb.55.1606
日期:——
was accomplished through a readily available spiro[4.5]decane. The key features of the synthesis of 1 and 2 include Claisen rearrangement to afford the multi-functionalized spiro[4.5]decane 4 as a single diastereomer in excellent yield, installation of the C7 isopropyl group via ketene dithioacetal instead of direct alkylation and a diastereoselective reduction of ketone under the Birch conditions.
Silicon guided rearrangement of epoxydecalines to spirocyclic compounds. Synthesis of gleenol and axenol from carvone
作者:Gonzalo Blay、Ana M. Collado、Begoña García、José R. Pedro
DOI:10.1016/j.tet.2005.09.025
日期:2005.11
The synthesis of the spirocyclic sesquiterpenes (-)-gleenol and (-)-axenol in enantiomerically pure form has been achieved starting from R-(-)-carvone. The key step is the silicon guided acid-promoted rearrangement of a 9-trimethylsilyl-5,6-epoxy-noreudesmane prepared from 3-tiimethylsilyldihydrocarvone in several steps involving Robinson annulation, enone deconjugation and epoxidation. Acid treatment of the epoxy-noreudesmane gave a norspiroaxane as the main product, which was used as intermediate for the synthesis of two naturally occurring sesquiterpenes gleenol and axenol. (c) 2005 Elsevier Ltd. All rights reserved.
Short total synthesis of the spiro[4.5]decane sesquiterpene (−)-gleenol
作者:Kai Oesterreich、Dietrich Spitzner
DOI:10.1016/s0040-4020(02)00336-8
日期:2002.5
The spirocyclic sesquiterpene (−)-gleenol was prepared in five steps starting from (−)-methone via a di-olefin. The final spiro-ring system was made using the olefin metathesis reaction. The resulting ketone was selectively reduced to the natural product.