ISSN:
1434-4475
Keywords:
Carbene-carbene rearrangement
;
Oxirene participation
;
Photolysis, [2-13 C] 1-phenyl-2-diazo-1,3-butadione
;
Wolff rearrangement
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Labelled acetyl-benzoylcarbene (13) formed by photolytic nitrogen elimination from [2-13C]1-phenyl-2-diazo-1,3-butadione (8) rearranges in the presence of ethanol to ethyl 2-phenylacetoacetate (26%) and ethyl 2-benzoylpropionate (74%). The13C-labelling in ethyl 2-phenylacetoacetate is found to the extend of ca.58% in the ester carbonyl function (20) and to ca. 42% in the adjacent tertiary carbon atom (21). This proves the isomerisation of carbene13 to carbene11 via the intermediate acetyl-phenyloxirene (12). The [1-13C]-labelled ester20 is formed by acetyl migration in11 to the ketene16 and subsequent addition of ethanol. In contrast, ethyl 2-benzoylpropionate is exclusively generated by migration of the methyl group in carbene13 since it contains the complete13C-labelling at the tertiary carbon atom (22).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00911927
Permalink
