Platinum- and Gold-Catalyzed Rearrangement Reactions of Propargyl Acetates: Total Syntheses of (−)-α-Cubebene, (−)-Cubebol, Sesquicarene and Related Terpenes
作者:Alois Fürstner、Peter Hannen
DOI:10.1002/chem.200501299
日期:2006.4.3
the carbophilic transition-metal cation. Formal attack of the alkene moiety onto the resulting pi-complex engenders the formation of an electrophilic cyclopropyl carbene species which subsequently reacts with the adjacent acetate unit to give the final product. The alternative phasing of events, implying initial attack of the acetate (rather than the alkene moiety) onto the metal-alkyne complex, is
Divergent Photocyclization/1,4-Sigmatropic Rearrangements for the Synthesis of Sesquiterpenoid Derivatives
作者:Evgueni Gorobets、Norman E. Wong、Robert S. Paton、Darren J. Derksen
DOI:10.1021/acs.orglett.6b03635
日期:2017.2.3
Combined experimental and computational efforts have demonstrated the utility of divergent photocyclization/1,4-sigmatropic rearrangement reactions for developing a general strategy toward the synthesis of cubebane-, spiroaxane-, and guaiane-type sesquiterpenes and related analogues. The configuration of the bridgehead substituent, the choice of solvent, and the wavelength of irradiation all impact
Stereocontrolled Syntheses of (−)-Cubebol and (−)-10-Epicubebol Involving Intramolecular Cyclopropanation of α-Lithiated Epoxides
作者:David M. Hodgson、Saifullah Salik、David J. Fox
DOI:10.1021/jo9022974
日期:2010.4.2
syntheses of 7-epicubebol (33) and (from (+)-menthone) of naturally occurring (−)-10-epicubebol (39), confirming the original structural assignment. Computational studies support the origin of the inversion as being rate-determining formylation of cis-enolate 27 from a mixture of rapidly interconverting enolates. In the synthesis of 7-epicubebol (33), allylic tertiary C−H insertion is observed as a significant
Synthesis of (−)-Cubebol by Face-Selective Platinum-, Gold-, or Copper-Catalyzed Cycloisomerization: Evidence of Chirality Transfer and Mechanistic Insights
作者:Charles Fehr、Beat Winter、Iris Magpantay
DOI:10.1002/chem.200901292
日期:2009.9.28
describe in detail a direct, stereoselective synthesis of (−)‐cubebol based on a Pt‐, Au‐, or Cu‐catalyzed cycloisomerization in which control of the configuration of the propargylic center is essential for the facial selectivity. In addition, we show that cycloisomerization reactions of enantioenriched propargyl pivalates occur with substantial chiralitytransfer. We confirm a mechanism by means of cyclization