Flash photolysis of 4-diazoisochroman-3-one in aqueous solution. Hydration of the carbene produced by loss of nitrogen and ketonization of the enol hydration product
✍ Scribed by Y. Chiang; S. J. Eustace; E. A. Jefferson; A. J. Kresge; V. V. Popik; R.-Q. Xie
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 104 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0894-3230
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✦ Synopsis
Flash photolysis of 4-diazoisochroman-3-one in aqueous solution resulted in loss of nitrogen and transient production of the a-carbonylcarbene 3-ketoisochroman-4-ylidene, the hydration of which generated a shortlived species that was identified as the enol isomer of the lactone, 4-hydroxyisochroman-3-one. This assignment is supported by x-ray crystallographic determination of the structure of the final lactone product, by the shape of the rate profile for ketonization of the enol intermediate to the lactone, and by solvent isotope effects on, and the form of acidbase catalysis of, the ketonization reaction.