'' Cyclisation / Desymmetrisation Reactions of Cyclohexa-1,4-Dienes'' Desymmetrisation of Cyclohexa-1,4-Dienes via Sulfoxide, Radical and Lewis acid mediated Prins Cyclizations Reactions''

, Nahed El-Sayed . 2015
نوع عمل المنشور
مدينة النشر
Heinrich-Böcking-Straße 6-8, Germany
اسم الناشر
Lambert academic Publishing
تاريخ المؤتمر
ملخص المنشورات

This work describes different strategies to desymmetrise 1,4-cyclohexadiene
derivatives with concomitant formation of a quaternary stereogenic centre.
Chapter 1 briefly describes the previous desymmetrisation processes of 1,4-
cyclohexadiene derivatives. Chapter 2 describes the formation of the
quaternary stereogenic centre using achiral cyclohexa-1,4-dienone
derivatives. Stereoselective formation of a quaternary stereogenic centre
was achieved using a chiral sulfinyl group as the stereodirecting influence
during the cyclisation step. Chapter 3 outlines attempts to improve the
level of the obtained diastereoselectivity. Chapter 4 describes the
desymmetrisation of the two diastereotopic double bonds of derivatives of
cyclohexa-1,4-diene using free-radical methodology. Chapters 5 describes
using Prins cyclisation reaction to desymmetrize the two diastereotopic
double bonds of 1,4-cyclohexadiene derivatives. This approach afforded an
easy and stereocontrolled access to fused tetrahydropyrans and
tetrahydrofurans depending on the reaction conditions employed. The
stereochemical outcome of all of these reactions was rationalised by a
single transition state model

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