Nitrone and nitrile oxide cycloadditions to bicyclopropylidene. Rearrangement of the isoxazolidine adducts to 3-spirocyclopropane-4-pyridone derivatives
作者:Alberto Brandi、Andrea Goti、Sergei Kozhushkov、Armin de Meijere
DOI:10.1039/c39940002185
日期:——
The two-step nitrone or nitrile oxide cycloaddition–rearrangement thermal process applied to bicyclopropylidene gives 4-pyridone, 7-indolizinone, and 2-quinolizinone derivatives containing a spirocyclopropane linkage α to a carbonyl group.
Brandi Alberto, Goti Andrea, Kozhushkov Sergei, de Meijere Armin, J. Chem. Soc. Chem. Commun, (1994) N 18, S 2185-2186
作者:Brandi Alberto, Goti Andrea, Kozhushkov Sergei, de Meijere Armin
DOI:——
日期:——
Thermal Rearrangement of Nitrone and Nitrile Oxide Cycloadducts to Bicyclopropylidene.<sup>1</sup> Synthesis of 3-Spirocyclopropane-4-pyridone and Furo[2,3-<i>c</i>]pyridine Derivatives
作者:Andrea Goti、Beatrice Anichini、Alberto Brandi、Sergei Kozhushkov、Corinna Gratkowski、Armin de Meijere
DOI:10.1021/jo951838l
日期:1996.1.1
The same sequence of cycloaddition and rearrangement can be achieved in a "one-pot" operation with considerable benefit for the reaction yield. Bisspirocyclopropaneisoxazolines obtained from nitrile oxides are more stable than their saturated counterparts and rearrange only at higher temperature less chemoselectively. Opening of both spiro-fused cyclopropylrings followed by aromatization produces interesting
Cyclopentene Anellation on Assorted Heterocyclic Skeletons by Vinylcyclopropane Rearrangement
作者:Alberto Brandi、Stefano Cicchi、Melanie Brandl、Sergei I. Kozhushkov、Armin de Meijere
DOI:10.1055/s-2001-11396
日期:——
Several α-spirocyclopropanated heterocyclic ketones were converted to the corresponding cyclopentene-anellated heterocycles in moderate to good yields (overall 31-60%) by Wadsworth-Emmons olefination followed by thermal rearrangement of the formed vinylcyclopropanes. In this sequence, the phosphonoacetonitrile was found to be superior to phosphonoacetate in the Wadsworth-Emmons olefinations of tetrahydropyridones.