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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
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Photoinduced and ground state conversions in a cyclic β-thioxoketone
Mariusz Pietrzak1, Joanna Buczyńska1, Fritz Duus2
1Institute of Physical Chemistry, Polish Academy of Sciences Kasprzaka 44 01-224 Warsaw Poland mpietrzak@ichf.edu.pl.
RSC Advances
|April 15, 2022
Summary
This study explores the photochemistry of a cyclic β-thioxoketone, revealing novel enethiol isomers and keto-form products through low-temperature and ambient-temperature experiments.
Area of Science:
- Photochemistry
- Organic Chemistry
- Spectroscopy
Background:
- Cyclic β-thioxoketones exist as tautomeric enol and thiol forms.
- Understanding their photochemical behavior is crucial for synthetic applications.
Purpose of the Study:
- To investigate the photochemistry of 2-methyl-1-(2-thioxycyclohexyl)propan-1-one (MTPO).
- To elucidate the mechanisms of photoconversion in the absence and presence of water.
Main Methods:
- Nuclear Magnetic Resonance (NMR) spectroscopy
- Ultraviolet (UV) and Infrared (IR) spectroscopy
- Density Functional Theory (DFT) calculations
Main Results:
- Low-temperature irradiation induced cis-trans isomerization of the thiol form, yielding enethiol isomers (3 and 4).
- Photochemical reactions at ambient temperature, involving water, produced a different keto-form (5).
- The keto-form (5) was also observed when low-temperature products were stored in the dark at ambient temperature.
Conclusions:
- MTPO undergoes complex photochemical transformations, including isomerization and hydration.
- The presence of water significantly influences the reaction pathway and product formation.
- Novel enethiol isomers were generated, expanding the understanding of thioxoketone photochemistry.
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