- Formation of Cyclic Carbonates in the Reaction of 1,2-Ditertiary Diols with Acetic Anhydride and 4-(Dimethylamino)pyridine
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The reaction of 1,2-ditertiary diol 1a with acetic anhydride and 4-(dimethylamino)pyridine (DMAP) at high concentrations in the absence of solvent has been found to give rise to cyclic carbonate 2a.The reaction has been generalized with a few other 1,2-ditertiary diols (1b-d).Based on the different products isolated in these reactions, apart from a small amount of normal acetylation products, various mechanisms have been proposed and examined.Tertiary alcohols have been found to give monoacetoacetates in addition to the acetates, under the same conditions.Detailedinvestigations have prompted us to suggest the intermediacy of ketene and diketene in these reactions.
- Bhushan, Vidya,Chakraborty, Thushar K.,Chandrasekaran, Srinivasan
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p. 3974 - 3978
(2007/10/02)
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- Anodic Fragmentation of O-Acylated α-Hydroxy Carboxylic Acids
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Depending on the degree of substitution at the α-carbon atom, the electrolyses of O-acylated α-hydroxy carboxylic acids 1 yield products of fragmentation (aldehydes or ketones 5) and products derived from acylium ions 4 in concurrence with simple anodic substitution products (acylales, amides, and imides, respectively).Dioxiranyl cations 2 are involved as intermediates.The fragmentation of the dioxiranyl cation 2 is investigated by semiempirical MINDO/3 calculations (Scheme 1).
- Thomas, Hans G.,Gabriel, Juergen,Fleischhauer, Joerg,Raabe, Gerhard
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p. 375 - 388
(2007/10/02)
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