- Stereoelectronic Model to Explain Highly Stereoselective Reactions of Seven-Membered-Ring Oxocarbenium-Ion Intermediates
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Nucleophilic attack on seven-membered-ring oxocarbenium ions is generally highly stereoselective. The preferred mode of nucleophilic attack forms the product in a conformation that minimizes transannular interactions, thus leading to different stereoselectivity as compared to that of reactions involving six-membered-ring oxocarbenium ions.
- Beaver, Matthew G.,Buscagan, Trixia M.,Lavinda, Olga,Woerpel
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supporting information
p. 1816 - 1819
(2016/02/03)
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- Acid-amplifier having acetal group and photoresist composition including the same
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An acid-amplifier having an acetal group and a photoresist composition including the same, are disclosed. The acid-amplifier produces an acid (second acid) during a post-exposure-bake (PEB), which is induced by an acid (first acid) generated from a photo-acid generator (PAG) at the exposure process so that a line edge roughness (LER) of the photoresist pattern and photoresist energy sensitivity are improved. The acid-amplifier has a structure of following Formula 1. in Formula 1, R is C4~C20 mono-cyclic or multi-cyclic saturated hydrocarbon, R1 is C1~C10 linear hydrocarbon, C1~C10 perfluoro compound or C5~C20 aromatic compound, Ra and Rb are independently hydrogen atom or C1~C4 saturated hydrocarbon and A is independently oxygen atom (O) or sulfur atom (S).
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Page/Page column 8
(2009/02/10)
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- REGIOSELECTIVE REDUCTIONS OF 2,3-EPOXY ACETALS WITH ZINC-CHLOROTRIMETHYLSILANE AND LITHIUM ALUMINIUM HYDRIDE: CONVENIENT SYNTHESIS OF 1,2 AND 1,3-DIONES
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A variety of 2,3-epoxy acetals have been found to undergo regioselective reductions with zinc-chlorotrimethylsilane and lithium aluminium hydride to give 2-hydroxy and 3-hydroxy acetals respectively.Their oxidation followed by hydrolysis furnished the corresponding 1,2- and 1,3-diones in good yields.
- Vankar, Yashwant D.,Chaudhuri, Narayan C.,Rao, C. Trinadha
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p. 551 - 554
(2007/10/02)
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