Organic Reaction Mechanisms - 1998: An Annual Survey Covering the Literature Dated December 1997 to November 1998. Edited by A. C. Knipe and W. E. Watts Copyright ¶ 2003 John Wiley & Sons, Ltd. ISBN: 0-471-49017-2 CHAPTER 1
Reactions of Aldehydes and Ketones and their Derivatives B. A. MURRAY Department of Applied Sciences, Institute of Technology Tallaght, Dublin, Ireland Formation and Reactions of Acetals and Related Species . . . . . . Reactions of Glucosides and Nucleosides . . . . . . . . . . . . . . . . . . Reactions of Ketenes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Formation and Reactions of Nitrogen Derivatives . . . . . . . . . . . Imines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Iminium Ions and Related Species . . . . . . . . . . . . . . . . . . . . . . Oximes, Hydrazones, and Related Species . . . . . . . . . . . . . . . . C−C Bond Formation and Fission: Aldol and Related Reactions Regio-, Enantio-, and Diastereo-selective Aldol Reactions . . . . . . Mukaiyama and Other Aldol-type Reactions . . . . . . . . . . . . . . . Allylations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other Addition Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . General and Theoretical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydration and Related Reactions . . . . . . . . . . . . . . . . . . . . . . . Addition of Organometallics . . . . . . . . . . . . . . . . . . . . . . . . . . Miscellaneous Additions . . . . . . . . . . . . . . . . . . . . . . . . . . . . Enolization and Related Reactions . . . . . . . . . . . . . . . . . . . . . . Enolates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oxidation and Reduction of Carbonyl Compounds . . . . . . . . . . Regio-, Enantio-, and Diastereo-selective Redox Reactions . . . . . Other Redox Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Formation and Reactions of Acetals and Related Species A comprehensive ab initio computational study of the anomeric effect in 1,3-dioxa systems has been designed to quantify anomeric effects in such compounds.1 Energy changes associated with O-protonation (and deprotonation, where relevant) have been calculated for tetrahydropyran, its 2-hydroxy derivative, and for 1,3-dioxane, together with acyclic comparators such as methanol, dimethyl ether, and methoxymethanol. All major conformations have been treated and their geometric parameters quantified. The 3-oxaalkoxides exhibit a preference for axial (nπ ) over equatorial (nσ ) protonation, by 2–3 kcal mol−1 . The COCOC acetals are stronger bases (at the acceptor oxygen)
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