- Synthesis of the Ring C Pyrrole of Native Chlorophylls and Bacteriochlorophylls
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As part of a program to develop practical syntheses of members of the family of (bacterio)chlorophylls, two routes to 2-iodo-3-methyl-4-(3-methoxy-1,3-dioxopropyl)pyrrole, a precursor of the universal ring C, have been developed. The β-ketoester of ring C
- Wang, Pengzhi,Chau Nguyen, Khiem,Lindsey, Jonathan S.
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- Unusually Facile Thermal Homodienyl-[1,5]-Hydrogen Shift Reactions in Photochemically Generated Vinyl Aziridines
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A range of photochemically generated tri- and tetracyclic vinyl aziridines have been found to undergo a general and surprisingly low temperature ring opening through a [1,5]-hydrogen shift reaction. The rate of the process was found to be highly dependent on the structure and substitution around the azirdine ring and the alkene terminus, with some substrates being observed to undergo ring opening at temperatures as low as 25 °C. The rigid nature of these polycyclic systems precludes a conformational explanation of these rate differences, and an Eyring study confirmed a negligible entropic barrier to the reaction. However, the Eyring plots for two different aziridines systems showed a significant difference in their enthalpies of activation. It is therefore believed that the levels of aziridine ring strain, as well as electronic effects, are the dominant factors in this sequence.
- Knowles, Jonathan P.,Booker-Milburn, Kevin I.
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supporting information
p. 11429 - 11434
(2016/08/03)
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- Metabolic products of Aspergillus terreus. VIII. Astepyrone: A novel metabolite of the strain IFO 4100
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A novel metabolite named astepyrone and two other new metabolites were isolated from Aspergillus terreus IFO 4100, and their chemical structures were determined. The biosynthesis of astepyrone was also studied and this metabolite was proved to be formed t
- Arai,Yoshimura,Itatani,Yamamoto
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p. 925 - 933
(2007/10/02)
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