ChemInform Abstract: Asymmetric Diels‐Alder Reactions. Part 2. A Model to Account for the Diastereofacial Reactivity of (E)‐1‐(2′,3′,4′,6′‐Tetra‐O‐acetyl‐β‐D‐glucopyranosyloxy)‐3‐trimethylsiloxy# buta‐1,3‐diene and Its 2‐Methyl Derivative. X‐Ray Molecular Structure of (E)‐1‐(2′,3′,4′,6′‐Tetra‐O‐acetyl‐β‐D‐glucopyranosyloxy)‐3‐trimethylsiloxy# buta‐1,3‐diene and of (1R,6R,9R,10S)‐9‐Methyl‐10‐(2′,3′,4′,6′‐tetra‐O‐acetyl‐β‐D‐glucopyranosylo# xy)bicyclo(4.4.0)dec‐3‐ene‐2,5,8‐trione.

Abstract

AbstractThe different diastereofacial reactivities of the title compounds (I) already emerge in the Diels‐Alder reaction with (II); they are even more pronounced in reactions with cyclic dienophiles such as (VI) and (VII), where single cycloadducts are obtained from (Ib), while the previously reported reactions of (Ia) had yielded 89:11 and 86:14 mixtures of diastereomers (X‐ray analyses of (Ia) and (VIII), both having the space group P212121 with Z=4).