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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

Studies related to reductive cyclization of alkynes

李柏昌, Li, Pak-cheong. January 1976 (has links)
published_or_final_version / Chemistry / Master / Master of Philosophy
52

Lewis acid-catalyzed asymmetric atom and group transfer radical cyclization reactions

Zheng, Baofu., 鄭保富. January 2005 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
53

Explorations on transition metal-catalyzed enantioselective cyclization reactions and applications of thiourea ligands

Yang, Min, 楊敏 January 2005 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
54

Intramolecular arylation of vinylogous amides and urethanes

Chang, Steven January 1991 (has links)
A thesis presented in the University of the Witwatersrand for the degree of Doctor of Philosophy / AC 2018
55

Studies on the construction of O-heterocycles from carbohydrates via 1,3-dipolar cycloaddition.

January 1994 (has links)
by Fung Wing-chuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 57-59). / Abstract --- p.i / Acknowledgments --- p.ii / Biography --- p.iii / Abbreviation --- p.v-vi / Chapter 1. --- Introduction / Chapter 1.1 --- Natural O-heterocycles --- p.1 / Chapter 1.2 --- Methods for the construction of O-heterocycles --- p.5 / Chapter 1.3 --- Intramolecular nitrone cycloaddition in the construction of O-heterocycles --- p.9 / Chapter 2. --- Results and discussion / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Synthesis of 68,77,84 Via INC --- p.13 / Chapter 2.3 --- Acyclic INC of nitrones --- p.16 / Chapter 2.4 --- "Studies on 7-, 8-membered rings formation" --- p.24 / Chapter 3. --- Conclusions --- p.29 / Chapter 4. --- Experimental --- p.34 / Chapter 5. --- References --- p.57 / Chapter 6. --- List of spectra --- p.60 / Chapter 7. --- Appendices --- p.72
56

Studies on the construction of heterocycles from carbohydrates via intramolecular cyclization. / CUHK electronic theses & dissertations collection

January 1998 (has links)
by Yong-li Zhong. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (p. 234-246). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.
57

Synthetic studies of carbocycles from carbohydrates. / CUHK electronic theses & dissertations collection

January 2008 (has links)
An enone was synthesized from delta-D-gluconolactone in four steps, involving a one-pot TPAP oxidation-K2CO3-mediated intramolecular Horner-Wadsworth-Emmons (HWE) olefination as the key step. / In this thesis, a review regarding intramolecular direct aldol reaction from 1971 to 2008 is presented. The background information on pseudo-acarviosin, valiolamine and its containing compounds, gabosines and human glutathione transferase (hGST) is introduced. / Intramolecular direct aldol reaction was investigated for the construction of cyclohexanones and cycloheptanones from carbohydrates. Amine bases, amide bases and L-proline were employed to facilitate cyclization of 1,5- and 1,6-diketones successfully. These 1,5- and 1,6-diketones were prepared from carbohydrates by standard transformations. Different bases were employed to promote cyclization of 1,5-diketone derived from D-glucose to give cyclohexanones stereoselectively. / Intramolecular nitrile oxide-alkene cycloaddition (INOC) was studied with sugar derivatives having free hydroxyl groups. The INOC reaction, by incorporating chloramine-T and silica gel for the formation of nitrile oxide from oxime, proceeded smoothly with one, two, and four unmasked hydroxyl groups to give cyclopentanes and cyclohexanes. / The polyhydroxylated carbocycles constructed from sugars were successfully transformed into a variety of target molecules including pseudo-acarviosin, valiolamine and its containing compounds and gabosines. A series of 2-crotonyloxymethyl-(4 R,5R,6R)-4,5,6-trihydroxy-2-cyclohexenone (COTC) analogues as inhibitors of hGST were prepared in order to study the structure-activity relationships. / Cheng, Hau Man. / Adviser: Tony K. M. Shing. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3508. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 214-224). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
58

Stereo-controlled intramolecular nitrone-alkene cycloaddition reactions involving carbohydrates substances. / CUHK electronic theses & dissertations collection

January 2006 (has links)
Wong Wai Fun. / "June 2006." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 226-230). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese.
59

Synthetic studies on zoapatanol.

January 1998 (has links)
by Yip Ting. / Thesis submitted in 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 55-59). / Abstract also in Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.iii / Abbreviation --- p.iv / Chapter Part 1 --- Introduction --- p.1 / Chapter 1.1 --- General Background --- p.1 / Chapter 1.2 --- Review on the Published Syntheses of Zoapatanol --- p.2 / Chapter Part 2 --- Results and Discussion --- p.12 / Chapter 2.1 --- Synthetic Strategy --- p.12 / Chapter 2.1.1 --- Synthesis of Tertiary Alcohol46 --- p.14 / Chapter 2.1.2 --- Synthesis of Vinyl Bromide 55-Z --- p.15 / Chapter 2.1.3 --- Synthetic studies on39 --- p.18 / Chapter 2.1.4 --- Synthetic studies on40 --- p.19 / Chapter 2.2 --- Synthetic Strategy --- p.23 / Chapter 2.2.1 --- Synthesis of 79 - route1 --- p.24 / Chapter 2.2.2 --- Synthesis of 79 - route2 --- p.26 / Chapter 2.2.3 --- Synthesis of 79 - route3 --- p.28 / Chapter 2.2.4 --- Synthetic studies on free radical cyclization of79 --- p.30 / Chapter 2.2.5 --- Synthesis of83 --- p.31 / Chapter 2.2.6 --- Synthetic studies on carbanion cyclization of83 --- p.31 / Chapter Part 3 --- Conclusion --- p.33 / Chapter Part 4 --- Experimental --- p.34 / Chapter Part 5 --- References --- p.55
60

Construction of carbocycles from carbohydrates via 1,3-dipolar cycloadditions.

January 2007 (has links)
Kwok, Wun Sang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 147-152). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.iii / Abstract (Chinese Version) --- p.iv / Abbreviation --- p.v / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- General Background --- p.1 / Chapter 1.1.1 --- "1,3-Dipolar Cycloaddition" --- p.1 / Chapter 1.1.2 --- Structure of Preparation of Nitrile Oxide --- p.3 / Chapter 1.2 --- Intramolecular Nitrile Oxide Alkene Cyclization (INOC) --- p.7 / Chapter 1.2.1 --- INOC in Organic Synthesis --- p.7 / Chapter 1.2.2 --- Formation of Oximolactone as Unwanted Reaction in INOC --- p.10 / Chapter 1.2.3 --- Nitrile Oxide Alkene Cyclization with Free Hydroxyl Group --- p.11 / Chapter 1.3 --- Natural Occurring Gabosine --- p.14 / Chapter 1.3.1 --- "Structure, Biological Effect and Syntheses of Gabosines" --- p.14 / Chapter 1.3.2 --- Synthesis of Gabosine O and its 4-epimer --- p.17 / Chapter 1.4 --- Protected 6-dehydroxy-Pseudo-a-D-Talose --- p.21 / Chapter 1.4.1 --- Structures and Biological Effects of Valienamine and its Derivatives --- p.21 / Chapter 1.4.2 --- Structural and Biological Studies of Valienamine by Our Group --- p.23 / Chapter 2. --- Results and Discussion --- p.28 / Chapter 2.1 --- Studies on INOC of Sugar Derivatives with Free Hydroxyl Group(s) --- p.28 / Chapter 2.2 --- Enantiospecific Synthesis of 4-epi-Gabosine O --- p.47 / Chapter 2.3 --- Enantiospecific Synthesis of Gabosine O --- p.84 / Chapter 2.4 --- Synthesis of 6-Deoxy-Pseudo-a-D-Talose --- p.87 / Chapter 3. --- Conclusion --- p.95 / Chapter 4. --- Experimental --- p.100 / References --- p.147 / Appendix NMR spectra --- p.153

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