钝化立体化学结果 a partir des cis-et trans-phenyl-5 diazo-5 pentenes, trans-diphenyl-1,4 dizo-4 butene-1 et cis-methyl-3 aryl-6 diazo-6 hexenes-3 montrent que les 反应 de cycloaddition-1,1 和retrocycloaddition-1,1 sont 立体选择性 avec 保留 de configuration total。分析 芳基-5 重氮-5 甲基-2 戊烯-2 反应电影
钝化立体化学结果 a partir des cis-et trans-phenyl-5 diazo-5 pentenes, trans-diphenyl-1,4 dizo-4 butene-1 et cis-methyl-3 aryl-6 diazo-6 hexenes-3 montrent que les 反应 de cycloaddition-1,1 和retrocycloaddition-1,1 sont 立体选择性 avec 保留 de configuration total。分析 芳基-5 重氮-5 甲基-2 戊烯-2 反应电影
Heterogeneous permanganate oxidations: Synthesis of medium ring keto-lactones via substituent directed oxidative cyclisation
作者:Jagattaran Das、Srinivasan Chandrasekaran
DOI:10.1016/s0040-4020(01)85664-7
日期:1994.1
Homoallyl alcohols 4a-b and 5a-b undergo smooth oxidative cyclisation to give the corresponding ring enlarged keto-lactones under heterogeneouspermanganateoxidation conditions.
Microwave-assisted regioselective olefinations of cyclic mono- and di-ketones with a stabilized phosphorus ylide
作者:Jinlong Wu、Dan Li、Huafeng Wu、Lijie Sun、Wei-Min Dai
DOI:10.1016/j.tet.2005.12.060
日期:2006.5
4-cyclohexanediones with the ylide at 190 °C for 20 min in MeCN afforded the exocyclicolefins in >94:6 isomer ratios. On the other hand, the same reactions carried out at 230 °C for 20 min in the presence of 20 mol % DBU furnished the endocyclicolefins in >83:17 isomer ratios. The base-mediated isomerization of the exocyclicolefins into the endocyclic isomers was primarily driven by thermodynamic stability of the
A new efficient decarboxylative reduction of γ-carbamoyloxy-α,β-unsaturated esters with lithium dialkylcuprate
作者:Toshiro Ibuka*、G. -Namg Chu、Fumio Yoneda
DOI:10.1016/s0040-4039(01)91022-6
日期:1984.1
A new synthetically useful decarboxylative reduction of γ-carbamoyloxy-α,β-unsaturated esters with lithium dialkylcuprate under mild condition was described.
heterocycles by the repeated treatment of borontrifluoride etherate (BF3-OEt2) is reported. The overall transformation from ketones 1 to spiro-fused indenes 3 proceeds via Wittig olefination, deconjugation, Grignard addition, and intramolecular electrophilic cyclization in moderate yields. It presents a novel rearrangement reaction catalyzed by borontrifluoride etherate and broadens the scope of application