ChemInform Abstract: Electrochemical Reduction of Halogenoketones. Part 2. Behavior of Cyclic 2‐Bromo‐ and 2‐Chloroketones.

Abstract

The electrochemical reduction of the halosubstituted cyclic ketones (I) at a mercury cathode gives the ketones (II) and (III).

Electrochemical Carboxylation of N-(2-Bromopropionyl)-4R- phenyloxazolidin-2-one: An Efficient Route to Unsymmetrical Methylmalonic Ester Derivatives

“…They could be converted into the corresponding chiral diol derivative by reduction (after activation). 1 The electrochemical methodology permits the carboxylation 3 in the R-position to carbonyl groups by direct reduction of R-haloketones in the presence of carbon dioxide 4,5 (50-57% yields in R-ketocarboxylic acids) or by direct reduction of vinyl triflates also in the presence of carbon dioxide 6,7 (28-77% yields in cyclic R-ketocarboxylic acids and 33-67% yields in linear ones). To our knowledge, no electro- Here we report our preliminary results for the electrochemical carboxylation of N-(2-bromopropionyl)-4R-phenyloxazolidin-2-one aimed at the synthesis and chiral resolution of unsymmetrical methylmalonic ester derivatives.…”

“…1 H NMR δ (CDCl3): 7.40-7.25 (m, 5H, ar), 5.46 (dd, 1H, J ) 8.9 Hz, J ) 3.7 Hz, OCHH), 4.70 (t, 1H, J ) 8.9 Hz, N.-CH), 4.53 (q, 1H, J ) 7.2 Hz, CHCO2CH3), 4.29 (dd, 1H, J ) 8.9 Hz, J ) 3.7 Hz, OCHH), 3.71 (s, 3H, CO2CH3), 1.40 (d, 3H, J ) 7.2 Hz, CH3CHCO2CH3). 13 5.44 (dd, 1H, J ) 9.0 Hz, J ) 3.9 Hz, OCHH), 4.71 (t, 1H, J ) 9.0 Hz, N.-CH), 4.49 (q, 1H, J ) 7.2 Hz, CHCO2CH3), 4.25 (dd, 1H, J ) 9.0 Hz, J ) 3.9 Hz, OCHH), 3.67 (s, 3H, CO2CH3), 1.39 (d, 3H, J ) 7.2 Hz, CH3CHCO2CH3). 13 To test the applicability of this electrochemical carboxylation, the investigation was extended to N-(R-bromoacyl)-4R-phenyloxazolidin-2-ones other than the title one (see Table 2).…”

“…The electrochemical methodology permits the carboxylation in the α-position to carbonyl groups by direct reduction of α-haloketones in the presence of carbon dioxide , (50−57% yields in α-ketocarboxylic acids) or by direct reduction of vinyl triflates also in the presence of carbon dioxide , (28−77% yields in cyclic α-ketocarboxylic acids and 33−67% yields in linear ones). To our knowledge, no electro- chemical carboxylation of α-haloesters or amides has been reported.…”