ORA Thesis: "The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids" - uuid:2c91155f-0c0d-47b4-b8dc-f5e32fb2a8f9

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Reference: Sarah J. Macnaughton, (2011). The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids. DPhil. University of Oxford.

Citable link to this page: http://ora.ox.ac.uk/objects/uuid:2c91155f-0c0d-47b4-b8dc-f5e32fb2a8f9
 
Title: The Aza-Bohlmann cyclisation and the synthesis of Pandanus alkaloids

Abstract:

Bohlmann et al. reported the oxidative spirocyclisation of 2-(ω-hydroxyalkyl)furans under Clauson-Kaas conditions to furnish 1,6-dioxaspiro[4.5]dec-3-enes, thereafter termed the “Bohlmann cyclisation.” This thesis describes the development of an analogous aza-Bohlmann cyclisation. Treatment of 2-(ω-aminoalkyl)furans with m-CPBA or singlet oxygen generates hydroxy- or methoxybutenolides, respectively, which undergo spirocyclisation upon treatment with H₂SO₄ to generate [4.4]- and [4.5]-spiroaminoacetals.

The axial/equatorial preferences of N-sulfonylspiroaminoacetals featuring a 3-O-isovaleryl or 3-O-benzyl substituent are described. Acid-catalysed equilibration revealed that in acetonitrile the axial isomer is thermodynamically favoured for both substrates.

The first total synthesis of the spiroaminoacetal alkaloid pandamarilactone-1 is discussed, via an aza-Bohlmann cyclisation, in 13 steps and 3% overall yield from 4-pentyn-1-ol.


Digital Origin:Born digital
Type of Award:DPhil
Level of Award:Doctoral
Awarding Institution: University of Oxford
Notes:This thesis is not currently available via ORA.
About The Authors
institutionUniversity of Oxford
facultyMathematical,Physical & Life Sciences Division - Chemistry - Organic Chemistry
researchGroupDr. Jeremy Robertson
oxfordCollegeLinacre College
 
Contributors
Dr Jeremy Robertson More by this contributor
RoleSupervisor
 
Dr Jonathan Dallimore More by this contributor
RoleSponsor
 
Bibliographic Details
Issue Date: 2011
Copyright Date: 2012
Identifiers
Urn: uuid:2c91155f-0c0d-47b4-b8dc-f5e32fb2a8f9
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Member of collection : ora:thesis
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Copyright Holder: Sarah Macnaughton
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