Addition and Ring Expansion Reactions of Tricarbonyl(1,2-dioxobenzocyclobutene)chromium(0) with Carbon Nucleophiles – Unexpected Formation of Benzocycloheptene Derivatives and the First Head-to-Head Coupling of Two Methoxyallene Molecules
✍ Scribed by Beate Voigt; Michael Brands; Richard Goddard; Rudolf Wartchow; Holger Butenschön
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 216 KB
- Volume
- 1998
- Category
- Article
- ISSN
- 1434-193X
No coin nor oath required. For personal study only.
✦ Synopsis
Addition of carbon nucleophiles to (benzocyclobutene-
Cope rearrangement followed by an intramolecular aldol addition. This is also the case with lithiated methoxyallene, dione)tricarbonylchromium(0) (4) results in the formation of exo mono-and diadducts as well as 1,2-diketones as the and as the result the first head-to-head coupling product 12 of two methoxyallene molecules is isolated in good yield. 12 consequence of proximal ring-opening reactions. In one case the unexpected formation of benzocycloheptenedione is used as a diene in Diels-Alder cycloadditions, and its molecular structure is compared to that of the similar complexes is observed. Treatment of 4 with an excess of 1ethoxy-1-lithioethene gives the product of a dianionic oxy-molecule 13, lacking the two exo methylene substitutents.