scholarly journals Aza-Cope Rearrangement−Mannich Cyclizations for the Formation of Complex Tricyclic Amines:  Stereocontrolled Total Synthesis of (±)-Gelsemine

2005 ◽  
Vol 127 (51) ◽  
pp. 18046-18053 ◽  
Author(s):  
William G. Earley ◽  
Jon E. Jacobsen ◽  
Andrew Madin ◽  
G. Patrick Meier ◽  
Christopher J. O'Donnell ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Cope Rearrangement

Taxane Diterpene Synthesis Studies. Part 2: Towards Taxinine—Enantiospecific Construction of an AB-ring Substructure Incorporating both Quaternary Carbon Centres and Attempts to Annulate the C-ring

2004 ◽  
Vol 57 (1) ◽  
pp. 53 ◽  
Author(s):  
Martin G. Banwell ◽  
Malcolm D. McLeod ◽  
Andrew G. Riches
Keyword(s):  
Total Synthesis ◽  
Cycloaddition Reaction ◽  
Ring System ◽  
Diels Alder ◽  
Biologically Active ◽  
Allylic Oxidation ◽  
Cope Rearrangement ◽  
Rearrangement Reaction ◽  
Ab Ring ◽  
Active Natural

In connection with efforts to develop an efficient total synthesis of the biologically active natural product taxinine 1, the enzymatically-derived and monochiral cis-1,2-dihydrocatechol 7 was converted, over several steps including a Diels–Alder cycloaddition reaction, into the bicyclo[2.2.2]octan-2-one 18. Reaction of the last compound with the organocerium reagent 22 afforded the 1,5-diene 23 which engaged in an anionic oxy-Cope rearrangement reaction to give, after C-methylation of the product enolate 25, bicyclo[5.3.1]undecenone 27 embodying the AB-ring system of target 1. Two methods for allylic oxidation of such products were developed and several unsuccessful attempts to effect a cyclization reaction so as to establish the taxane C-ring are described.

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