|dc.contributor.author||Forsyth, Angus C.||en
|dc.description.abstract||The cycloaddition of benzonitrile oxide to 2-alkoxy-5,6-
dihyclro-2H-pyrans was investigated with particular interest
in the factors affecting the regio- and stereoselectivity
of the reaction. The 2-methoxy analogue showed weak
activity and little selectivity. The isolated products
consisted of two by-products, three 1:1 cycloadducts and
three 2:1 cycloadducts. The -butoxy analogue afforded
only two cycloadducts. Both arose from attack anti to the
bulky alkoxy substituent.
Addition of benzonitrile oxide and Q,j-dipheny1njtrone to
a bridged pyran, 6,8-dioxabicyclo[3 .2. l]oct-3-ene, showed
similar selectivity and much enhanced reactivity.
Levoglucosenone, a chiral bicyclic enone showed excellent
reactivity and selectivity in reaction with benzonitrile
oxide. Two cycloadducts were isolated in a ratio of ca.
100:1 and a combined yield of 71%; the major adduct having
added from the face anti to the methyleneoxy bridge. This
isoxazoline was investigated further in reactions involving
reduction of the carbonyl group, acetal formation and
nucleophilic addition of nitromethane.
Levoglucosenone was also shown to be a reactive
dipolarophjle to other 1,3-dipoles such as nitrones, a
nitrile imine and a carbohydrate nitrile oxide. The
chemistry of some of these adducts was also investigated.
Finally, the Michael addition of nitromethane to
levoglucosenone was investigated under many different
conditions and with different basic catalysts. The aim was
to synthesise levoglucosenone with a primary nitro
substituent to use as a nitrile oxide precursor. The
series of reactions afforded 8 identifiable products, none
of which was the desired Michael adduct.||en
|dc.publisher||The University of Edinburgh||en
|dc.relation.ispartof||KB thesis scanning project 2015||en
|dc.title||1,3-dipolar cycloadditions to levoglucosenone and related cyclic alkenes||en
|dc.type||Thesis or Dissertation||en
|dc.type.qualificationname||PhD Doctor of Philosophy||en