by Fong Sun. / On t.p., "+" appears over "-". / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 41-43). / Acknowledgements --- p.i / Contents --- p.ii / Abstract --- p.iii / Abbreviations --- p.iv / Chapter I --- Introduction / Chapter I-1 --- General background --- p.1 / Chapter I-2 --- Literature survey --- p.3 / Chapter I-2-1 --- Ley's approach to β-ketomacrolides --- p.3 / Chapter I-2-2 --- Weiler's approach to β-ketomacrolides --- p.4 / Chapter I-2-3 --- Macrocyclic β-ketomacrolides formation through sulfide contraction ´ؤIreland's approach --- p.5 / Chapter II --- Result and Discussion / Chapter II-1 --- General strategy for the synthesis of 1 -oxa[n]metacyclophanes --- p.7 / Chapter II-2 --- l-Oxa[n]metacyclophanes as masked β-ketomacrolides synthons --- p.9 / Chapter II-3 --- Application to the synthesis of natural products --- p.10 / Chapter II-4 --- An alternate approach for the synthesis of (2E)-2-dodecen-l 1-olide´ؤA structural proof --- p.15 / Chapter III --- Conclusion --- p.17 / Chapter IV --- Experimental --- p.18 / Chapter V --- References --- p.41 / Chapter VI --- Spectra --- p.44

Isobenzofurans (IBF)s are interesting molecules with regards to their structure and reactivity. The properties of these compounds are investigated through the use of gas phase calculations and kinetic studies. This work provides insight into the aromatic character of IBF and how substituents affect IBF’s reactivity. Substituted derivatives of naphtho[1,2-c:5,6-c]difuran are synthesized and reacted with tethered bis(dienophile)s to form cyclophanes. Phenyl-substituted naphtho[1,2-c5,6-c]difuran forms only a single isomer when reacted with a tethered bis(acrylate) and a tert-butyldimethylsilyl-substituted derivative exhibits higher selectivity towards cyclophane formation rather than polymer formation. Evidence for strong intramolecular interactions within these cyclophanes is presented as well. A five-step synthesis of anthra[1,2-c:7,8-c]difuran is developed, although with a poor overall yield. Similar reaction conditions could be applied to the synthesis of anthra[1,2-c:5,6-c]difuran. We also propose the synthesis of two different aromatic belts from these compounds. / xxii, 122 leaves : ill. ; 29 cm.

The synthesis of 1,2-bis(5-isobenzofuranyl)ethene by two routes is described. The first route involved generation of 1,2-bis(5-isobenzofuranyl)ethene from a bis(acetal) precursor under basic conditions. However, the synthesis was lengthy with low-yielding steps, which led to it being abandoned. The second route involved generation of 1,2-bis(5-isobenzofuranyl)ethene from a bis(oxabicyclic) precursor with 3,6-di(2'-pyridyl)-s-tetrazine. Napththo[1,2-c:5,6-c] difuran and 1,2-bis(5isobenzofuranyl)ethene were used to construct novel cyclophanes by double Diels-Alder reactions with bis(maleimide)s. NMR, AM1 modeling, and X-ray studies of the cyclophanes are discused. Attempts to prepare phenanthro[2,3-c:6,7-c] difuran and its cyclophanes are discussed. None was successful, and investigations were hampered by the inability to obtain sufficient quantities of starting materials. Finally, several suggestions are given for improving the syntheses of 1,2-bis(5- isobenzofuranyl)ethene, phenanthro[2,3-c:6,7-c]difuran, and their cyclophanes. Future directions, such as the functionalization of the double bond of 1,2-bis(5-isobenzofuranyl)ethene, aromatization of the oxabicyclic rings of the cyclophanes, and further X-ray studies are discussed. / x, 122 leaves : ill. ; 28 cm.

Isobenzofuran has since its discovery proven an important intermediate in the synthesis of novel organic compounds, due to its high reactivity in Diels-Alder reactions. This thesis details the synthesis, purification and characterization of cyclophane compounds derived from a novel analogue of isobenzofuran, 5,5'-bi(isobenzofuran). Because of the relative rarity of molecules containing multiple isobenzofuran units, 5.5'-bi(isobenzofuran) is an excellent candidate for study. Prelminary analysis of an additional novel analogue of isobenzofuran, 5.5'-bis(isobenzofuranyl) acetylene, is also presented. / x, 119 leaves : ill. ; 29 cm.