𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Dimers of 3,7-dehydrotropones (bicyclo[3.2.0]hepta-1(7),2,4-trien-6-ones)

✍ Scribed by Barbara Szechner; Max Rey; André S. Dreiding; Rita Grieb

Publisher
John Wiley and Sons
Year
1984
Tongue
German
Weight
678 KB
Volume
67
Category
Article
ISSN
0018-019X

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

2‐(tert‐Butyl)‐3,7‐dehydrotropone (7‐(tert‐butyl)bicyclo[3.2.0]hepta‐1(7),2,4‐trien‐6‐one; 1) was found to dimerize reversibly to 2A by [2 + 4]‐cycloaddition/cycloreversion reaction. The equilibrium lies on the side of the highly strained dimer 2A in the solid state, and on the side of the monomer 1 in solution. The [2 + 4]‐reaction is fully perisite‐, regio‐ and stereoselective. Above room temperature, 1 irreversibly formed a decarbonylated dimer 6, probably via the intermediate 9A or 9B, which resulted either from a dimerisation of 1 by [4 + 6]‐cycloaddition or from a sigmatropic rearrangement of the originally formed dimer 2A or 2B. Similary, the 6‐bromo derivative 14 afforded the corresponding decarbonylated dimer 15. Should the formation of 6 and 15 be due to a primary cycloaddition then that reaction is fully peri‐, site‐ and regioselective. Mild LiAlH~4~‐reduction of 6 and subsequent acetylation yielded the acetate 11, the structure of which was established by an X‐ray analysis. More vigorous LiAlH~4~‐treatment also reduced the terminal fulvenoid double bond of 6 and acetylation of the crude product led to the acetated 12 and 13.

📜 SIMILAR VOLUMES

An analysis of the electronic structure
An analysis of the electronic structure of 6,7-dimethyl-3-oxabicyclo[3.2.0]hepta-1,4,6-triene
✍ Sustmann, Reiner ;Müller, Wolfgang ;Roth, Wolfgang R. ;Wittich, Dieter 📂 Article 📅 1985 🏛 Wiley (John Wiley & Sons) 🌐 English ⚖ 192 KB 👁 1 views

The geometry and the n-electronic structure of 6,7-dimethyl-3-oxabicyclo[3.2.O]hepta-l,4,6triene (4) is analyzed by M N D O calculations and by the interpretation of the He-I-photoelectron spectrum. The calculated bond length alternations in 4 indicate olefinic resp. antiaromatic character. As H O M

Polyhalogenierte Bicyclo[4.2.0]octa-1,5,
Polyhalogenierte Bicyclo[4.2.0]octa-1,5,7-triene, XI. Darstellung und Reaktionen von Bicyclo[4.2.0]octa-1,3,5-trien-7,8-diylsulfaten
✍ Roedig, Alfred ;Ganns, Eva Maria ;Ganns, Rainer 📂 Article 📅 1982 🏛 John Wiley and Sons 🌐 English ⚖ 715 KB

## Abstract Die cyclischen Schwefelsäureester **4a, d** und **e** werden aus **1a, d** und **e** mit Schwefelsäure bei Raumtemperatur dargestellt. Bei höherer Temperatur entstehen die Diketone **3a** oder **b**. Sowohl die Thermolyse der Schwefelsäureester bei 180–200°C als auch ihre Säurehydrolyse

Pyrolyze von 1,2,3,5,6,7-Hexachlor-4-met
Pyrolyze von 1,2,3,5,6,7-Hexachlor-4-methylenbicyclo[3.2.0]hepta-2,6-dienen
✍ Roedig, Alfred ;Försch, Manfred 📂 Article 📅 1978 🏛 Wiley (John Wiley & Sons) ⚖ 538 KB

## Abstract Die Titelverbindungen **6/7** sind in einer zwei‐ oder dreistufigen Synthese aus dem bicyclischen Keton **1** erhältlich. Im Fall **6/7c** konnten __Z__‐ und __E__‐Isomeres voneinander getrennt werden. Die Kurzzeitpyrolyse im Hochvakuum bei 460°C liefert die entsprechenden Styrol‐ bzw.