Beilstein J. Org. Chem.2013,9, 36–48, doi:10.3762/bjoc.9.5
Reiner Stamm Henning Hopf Institut für Organische Chemie, Technische Universität Braunschweig, Hagenring 30, D-38106 Braunschweig (Germany), Fax: +49 (0)531 / 391 5388 10.3762/bjoc.9.5 Abstract The chemical behaviour of various alkyl-substituted, acyclic conjugatedbisallenes in reactions
transformations.
Keywords: β-lactams; conjugatedbisallenes; cyclopentenones; epoxidation; halogen addition; hydrohalogenation; ionic additions; metalation; Introduction
Whereas the use of hexa-1,2,4,5-tetraene (1) and its derivatives in pericyclic reactions is well documented [2][3][4][5][6], relatively little
is known about the behavior of noncyclic, conjugatedbisallenes in ionic or polar reactions, whether these involve metalation processes, the addition of halogens and hydrogen halides, or oxidation reactions, to name but a few. To fill this gap we initiated a research program, hoping also that polar
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Graphical Abstract
Scheme 1:
The alkylated conjugated bisallenes 1– 3 as model systems for polar reactions.
Beilstein J. Org. Chem.2012,8, 1936–1998, doi:10.3762/bjoc.8.225
organic synthesis for the first time. All classes of compounds containing at least two allene moieties are considered, starting from simple conjugatedbisallenes and ending with allenes in which the two cumulenic units are connected by complex polycyclic ring systems, heteroatoms and/or heteroatom
steps (high step economy).
Keywords: alicyclic; bisallenes; cyclic; cycloadditions; cycloisomerization; isomerization; molecular complexity; step economy; Table of Contents
Introduction
Review
Acyclic conjugatedbisallenes
1.1 Synthesis of hydrocarbons
1.2 Synthesis of functionalized systems
1.3
Spectroscopic and structural properties of conjugatedbisallenes
1.4 The chemical behavior of conjugatedbisallenes
1.4.1 Pericyclic reactions
1.4.2 Ionic reactions
1.4.3 Metal-induced reactions
Acyclic nonconjugated bisallenes
2.1 1,2,5,6-Heptatetraene and its derivatives
2.2 1,2,6,7-Octatetraene and its
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Graphical Abstract
Figure 1:
Loschmidt’s structure proposal for benzene (1) (Scheme 181 from [3]) and the corresponding modern stru...