+44 (0)1509 263171
Please use this identifier to cite or link to this item:
|Title: ||Some aspects of the chemistry of cyclic aminol ethers|
|Authors: ||Sampler, Edward P.|
|Issue Date: ||2001|
|Publisher: ||© Edward Phillip Sampler|
|Abstract: ||This thesis has been divided into three main sections. The first chapter contains a
review of calixarene chemistry, in particular that relating to calix[4)resorcinarenes.
Results and discussion are compiled in chapters two through seven and experimental
details are provided in chapter eight.
Chapters two and three contain results and discussion relating to the novel synthesis
of the first example of an enantiomerically pure axially chiral resorcinarene derivative.
Chapter two outlines the key step in the reaction sequence, that being the
tetramethylation of diastereomerically pure tetrakis(3,4-dihydro-2H-1,3-
benzoxazine)calix[4)resorcinarene derivatives. Chapter three describes the
subsequent synthetic sequence developed to fragment 3,4-dihydro-2H-1,3-
benzoxazines with a view to removing the a-methylbenzylamine chiral auxiliary, which
was used to set up the observed axial chirality of the resorcinarene. The sequence
incorporates a novel modified Eschweiler-Clarke reaction whereby refluxing the
required tetrakis(3,4-dihydro-2H-1 ,3-benzoxazine)calix[4)resorcinarene derivative in
aqueous formic acid resulted in reductive ring opening, furnishing the N-methylated
Chapter four describes work on functionalising the 'lower rim' of resorcinarene
macrocycles with a view to forming derivatives with a pendant functional group that
could be manipulated further to support the newly formed axially chiral resorcinarene
derivatives onto solid supports.
Chapter five contains prelfminary investigations into the use of axially chiral
resorcinarene derivatives as chiral ligands in the enantioselective addition of
diethylzinc to benzaldehyde.
Chapter six contains results of investigations into the mechanism of the 'RetroMannich'
reaction, whereby an amine exchange reaction is observed when refluxing a
dihydro-1,3-benzoxazine or Mannich base in a high boiling amine such as
morpholine. Evidence has been provided that the reaction proceeds via an o-quinone
Chapter seven describes investigations into the generality of the modified EschweilerClarke
reductive ring opening methodology whereby refluxing a formic acid solution of
a cyclic aminol ether results in the formation of N,N-dialkyl derivatives via reductive
ring opening. It was found that the procedure was general for compounds without
sUbstituents at the two position. A second reaction protocol was developed for
compounds with substituents at the two position, utilising a combination of sodium
cyanoborohydride and chlorotrimethylsilane in acetonitrile to furnish the desired N,Ndialkyl
derivatives in excellent yield.
Finally, chapter eight contains full experimental details for the synthetic studies
carried out in the preceding chapters.|
|Description: ||A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.|
|Appears in Collections:||PhD Theses (Chemistry)|
Files associated with this item:
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.