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Updated: May 30, 2026

Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions
Published on: July 28, 2022
Diethyl 4,5-diphenyl-3,6-bis-(trimethyl-sil-yl)benzene-1,2-dicarboxyl-ate
Abstract:
In the title compound, C(30)H(38)O(4)Si(2), the two phenyl rings are twisted away from the central benzene ring by 70.28 (8) and 67.42 (7)°. The two Si atoms attached to the benzene ring deviate in opposite directions from the ring plane by 0.258 (3) and 0.206 (3) Å, respectively. One ethyl group is disordered over two conformations in a 0.568 (5):0.432 (5) ratio. The crystal packing exhibits weak inter-molecular C-H⋯O inter-actions.
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Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Diels–Alder Reaction: Characteristics of Dienes
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...

