Synthesis of trans-Fused Oxabicyclo[5.2.0]nonan-2-ones via [2+2] Photocycloaddition of Oxepinones to Conjugated Alkenes
作者:Kerstin Schmidt、Paul Margaretha
DOI:10.1002/hlca.201100009
日期:2011.5
On irradiation (350 nm) in the presence of 2,3‐dimethylbuta‐1,3‐diene, benzoxepinone 2 and dioxepinone 3 were converted regio‐ and diastereoselectively to trans‐fused oxabicyclo[5.2.0]nonanones 5 and 9, respectively.
Interconversion of cis- and trans-Fused Oxabicyclo[5.2.0]nonan-2-ones
作者:Kerstin Schmidt、Paul Margaretha
DOI:10.1002/hlca.201100203
日期:2011.11
presence of alkenes (2,3‐dimethylbut‐2‐ene, 1,1‐dimethoxyethene, and 2,4,4‐trimethylpent‐1‐ene), benzoxepinone 1 and dioxepinone 2 are converted into mixtures of cis‐ and trans‐fused oxabicyclo[5.2.0]nonan‐2‐ones. Their relative thermodynamic stabilities (as reflected by the observed diastereoisomer ratios after equilibration with basic alumina) depend on the substitution pattern of the alkene moiety
New synthetic approach to substituted 4,5-dihydro-1,3-dioxepines
作者:V. Yu. Fedorenko、T. V. Bulygina、Yu. G. Shtyrlin、E. N. Klimovitskii
DOI:10.1007/s11178-005-0110-5
日期:2004.12
Photocyclodimers of ‘Made-to-Measure’ Seven- and Six-Membered Cyclic Enones
作者:Kerstin Schmidt、Paul Margaretha
DOI:10.1002/hlca.201100406
日期:2012.3
On irradiation (350 nm) in benzene as solvent, dioxepinone 6 and benzoxepinone 7 afford quantitatively mixtures of two diastereoisomeric head‐to‐head dimers, respectively. In both cases, on contact with SiO2 the minor dimer containing trans‐ring fusions undergoes spontaneous isomerization to the (major) cis‐transoid‐cis diastereoisomer. In contrast, thiopyranone 8 is converted selectively, but in very