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Diels-Alder Reactions of Tetradehydrodianthracene with Electron-Rich Dienes

✍ Scribed by Kammermeier, Stefan ;Neumann, Helfried ;Hampel, Frank ;Herges, Rainer

Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
547 KB
Volume
1996
Category
Article
ISSN
0947-3440

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✦ Synopsis

Abstract

Tetradehydrodianthracene (TDDA; 1) reacts with electronrich dienes such as butadiene, cyclopentadiene and o‐quinodimethane under ambient conditions. Only 1:1 products 5–8 were observed even with a large excess of the diene and under drastic conditions (though two strained and highly pyramidalized double bonds are available). The enhanced reactivity of TDDA compared with its mono Diels‐Alder adducts is mainly due to the through‐bond and through‐space interaction of the two olefinic double bonds. During the cycloaddition one of the olefinic bonds in TDDA is converted into an extremely long C–C single bond (> 1.65 Å). Attempts to cleave the strained π‐bond thermochemically to form a diradical 13 afforded product 14a that was formed via a formal intramolecular homo 1,3‐sigmatropic shift.

📜 SIMILAR VOLUMES

Diels-Alder Reactions of Tetradehydrodia
Diels-Alder Reactions of Tetradehydrodianthracene with Electron-Deficient Dienes
✍ Sauer, Jürgen ;Breu, Josef ;Holland, Uwe ;Herges, Rainer ;Neumann, Helfried ;Kam 📂 Article 📅 1997 🏛 John Wiley and Sons 🌐 English ⚖ 758 KB

## Abstract Theoretical calculations and simple MO considerations predict that a coplanar and spatially close arrangement of double bonds in structures such as tetradehydrodianthracene 1, should both lower the LUMO and raise the HOMO energy of the π system. Thus the reactivity in Diels‐Alder reacti