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I. Thermal cyclization of (Z)-1,2,4-heptatrien-6-yne. II. Studies directed toward the synthesis of neocarzinostatin chromophore

Citation

Kuo, Elaine Y. (1993) I. Thermal cyclization of (Z)-1,2,4-heptatrien-6-yne. II. Studies directed toward the synthesis of neocarzinostatin chromophore. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/x7qa-8x77. https://resolver.caltech.edu/CaltechTHESIS:01102013-092055513

Abstract

The possibility that the hydrocarbon (Z)-1,2,4-heptatrien-6-yne might undergo a thermal cyclization to the biradical α,3-dehydroluene was considered. A methodology for the synthesis of (Z)-1,2,4-heptatrien-6-yne was developed wherein propargyl hydrazines, obtained from the corresponding propargyl alcohols, were oxidized to allenes with diethyl azodicarboxylate in good yields. The formation of products consistent with the intermediacy of the biradical α,3-dehydrotoluene is discussed.

In studies directed toward the total synthesis of neocarzinostatin chromophore, the attempted formation of the cyclononadiyne core of the molecule via the intramolecular insertion of an alkylidene carbene into an acetylenic carbon-hydrogen bond was investigated. The alkylidene carbene was generated from the appropriately functionalized cyclopentanone precursor with the reagent dimethyl diazomethylphosphonate (DAMP). While the identification of the reaction products was consistent with the formation of the desired carbene, the formation of the desired insertion product was not observed. In conjunction with studies seeking to synthesize neocarzinostatin chromophore via an intramolecular acetylide addition, the synthesis of an epoxy carbonate fragment to be used in the convergent synthesis of a suitable cyclization precursor is described, as well as initial efforts concerning glycosylation with a suitably protected N-methyl D-fucosamine derivative.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Chemistry
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Myers, Andrew G.
Thesis Committee:
  • Unknown, Unknown
Defense Date:12 March 1993
Record Number:CaltechTHESIS:01102013-092055513
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:01102013-092055513
DOI:10.7907/x7qa-8x77
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:7387
Collection:CaltechTHESIS
Deposited By: Benjamin Perez
Deposited On:10 Jan 2013 18:27
Last Modified:16 Apr 2021 22:32

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