ChemInform Abstract: Oxabicyclo[3.2.1]octenes in Organic Synthesis: Direct Ring Opening of Oxabicyclo[3.2.1] Ring Systems with Diisobutylaluminum Hydride and a Silyl Ketene Acetal - Synthesis of the Chiral C(19)-C(26) and C(27)-C(32) Fragments of Scytophy

ChemInform ◽  
2010 ◽  
Vol 33 (23) ◽  
pp. no-no
Author(s):  
Kevin W. Hunt ◽  
Paul A. Grieco
Keyword(s):  
Organic Synthesis ◽  
Ring Opening ◽  
Ring Systems ◽  
Diisobutylaluminum Hydride ◽  
Ketene Acetal ◽  
C 32

Tandem Suzuki Coupling/Intramolecular Oxetane Ring Opening to Form Polycyclic Ring Systems

2020 ◽  
Vol 22 (15) ◽  
pp. 5828-5832 ◽  
Author(s):  
Lindsey G. DeRatt ◽  
Edward C. Lawson ◽  
Kiran Kumar ◽  
Soyon S. Hwang ◽  
Renee L. DesJarlais ◽  
...  
Keyword(s):  
Ring Opening ◽  
Suzuki Coupling ◽  
Ring Systems ◽  
Oxetane Ring

Zur elektrocyclischen Ringöffnung von Cyclopropylhalogeniden bei der Reaktion mit Natriumiodid in Aceton / Electrocyclic Ring Opening of Cyclopropyl Halides in the Course of their Reaction with Sodium Iodide in Acetone

1979 ◽  
Vol 34 (3) ◽  
pp. 464-480 ◽  
Author(s):  
Reiner Luckenbach ◽  
Nikolaus Müller
Keyword(s):  
Kinetic Data ◽  
Ring Opening ◽  
Sodium Iodide ◽  
Strong Support ◽  
Hammett Equation ◽  
Kinetic Measurements ◽  
Ring Systems ◽  
First Order ◽  
Leaving Groups ◽  
Retained Products

Abstract Reaction of cyclopropyl halides with sodium iodide in acetone (i.e. under typical SN2-conditions), proceeds via ring opening to allylic systems finally yielding 1,5-hexadienes upon dimerisation; ring-retained products were not detected. Application of the Wood-ward-Hoffmann rules lends strong support to a cationic synchronous mechanism. This is also confirmed by kinetic measurements proving this reaction to be first order over all. The kinetic data are shown to fit the Hammett equation using σ-values for cyclopropyl bromides and σ+-values for geminal cyclopropyl dichlorides, respectively. The validity of the Woodward-Hoffmann-De Puyrule (according to which in synchronous reactions leaving groups situated endo are strongly favored over those situated exo) is tested in corresponding experiments involving condensed ring systems.

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