Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"Ketals"”.
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Mechanistic studies of diastereoselective cyclopropanations of homochiral ene-ketals and synthesis and resolution of diastereomeric alpha-hydroxycycloalkanone ketals.
A series of homochiral ene ketals were prepared and subjected to the Simmons-Smith cyclopropanation. A mechanistic model was formulated to explain the observed diastereoselectivity seen for the common ring systems. Diastereoselectivity is thought to result from preferential chelation of the …
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Brønsted acid-catalyzed reaction of alkynyltrifluoroborates with acetals and ketals
… bond forming methodology between acetals, ketals, and potassium phenylacetylene trifluoroborate salts. Excellent functional group tolerance is observed with this protocol including, halogen, nitrile, nitro, acid and carbonyl functionalities.
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Trifluoroethyl enol ethers, dienol ethers, and acetals: an investigation of their preparations, reactivities, and synthetic applications
… studied were trifluoroethoxy substituted ketals, enol ethers, and dienol ethers. The ketal and enol ether work involved developing methodology for the large scale preparation of these structures as well as studies detailing their behavior. For the TFE ketals, preparation involved an …
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Constituents of Aplysina Fistularis
… its monobromo analog and its ketals; and brominated phenylacetic acids were identified in the extracts of samples #852 and #947.
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A study of activated ketal reduction with borane dimenthyl sulphide
… recent times, is the dissociative reduction of ketals to afford ethers as protected secondary derivatives and a number of approaches accomplishing a high degree of stereoselectivity have been developed. This thesis describes a study of a novel reagent combination, namely borane dimethyl sulphide …
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I The synthesis of papyracillic acids: Application of the tandem chain extension-acylation reaction II Diastereoselective synthesis of beta-methyl-gamma-keto esters through the utility of an L-serine auxiliary
… reaction for the synthesis of spiro-fused ketals was successfully accomplished. The incorporation of a methyl-substituent into the gamma-keto ester backbone, through a methyl substituted carbenoid, allowed for the synthesis of papyracillic acid B and 4-epi-papyracillic acid C. Comparison …
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Asymmetric Synthesis of Homotropinone and Tropane Alkaloids using Enantiopure Sulfinimines and the Synthesis and Applications of Methanoprolines
… sulfinimine-derived N-sulfinyl ß-amino ketone ketals. These amino ketone ketal chiral building blocks were prepared in 67-71% yields and high dr (25-14:1) by addition of the Weinreb amide enolate of N-methoxy-Nmethylacetamide to masked oxo sulfinimines (N-sulfinyl imines). Treatment of these …
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New methodology for the organocatalysed α-Amination reaction
… broad substrates cope in its application to ketals, dioxolanes and lactols. A hydrazide N-N bond cleavage methodology was also developed for the aminated products in oxazolidinone form. This methodology is based on Magnus' alkylation / E1CB strategy. The novel contribution here is using …
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Stimuli-responsive microcapsules for self-protecting and self-healing material systems
… is achieved by integrating acid labile ketals that undergo rapid hydrolysis within the cross-linked polyamide shell and readily release acetylenic diol or jojoba oil as the anticorrosive agent. The microcapsules are stable up to a temperature of 150 °C and provide long-term room …