Internally hydrogen-bonded chiral methylenenitrones in cycloaddition reactions

(2006) Internally hydrogen-bonded chiral methylenenitrones in cycloaddition reactions. Masters thesis, King Fahd University of Petroleum and Minerals.


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English Abstract

1,3-Dipolar cycloaddition (DC) reactions of two chiral methylene nitrones, (R)-N-2-(1-hydoxy-2-phenyl ethyl)methylenenitrone (I) and (1R,2S,3R,4R)-N-3-(2-hydroxy-1,7,7-trimethylbicyclo[2.2.1]heptanyl)methylenenitrone (II), with a multitude of mono-, di-, and tri-substituted alkenes have been studied in detail. The nitrone (II) showed better face and stereoselectivity. The stereochemical outcome has been explained in terms of steric factors and secondary orbital interactions in the transition states. The effect of intramolecular hydrogen bonding has also been demonstrated. The DC reactions of the nitrone (I) in the presence of magnesium bromide have exhibited remarkable regio- and stereoselectivity. The improved selectivity has been rationalized using a metal chelated cyclic form of the nitrone. The findings of the study would indeed be useful in incorporating chiral centers in natural product synthesis.

Item Type: Thesis (Masters)
Subjects: Chemistry
Department: College of Chemicals and Materials > Chemistry
Committee Advisor: Ali, Shaikh Asrof
Committee Members: Fettouhi, M. B. and Al-Muallem, Hasan A.
Depositing User: Mr. Admin Admin
Date Deposited: 22 Jun 2008 14:07
Last Modified: 01 Nov 2019 14:02