Aromatic ring synthesis by 1,3-Michael-Claisen annulation: Formation of dihydrobenzofurans and tetrahydrochromans from α-methylene γ-butyrolactone and δ-valerolactone
摘要:
Substituted dihydrobenzofurans and tetrahydrochromans have been prepared from respectively alpha-methylene-gamma-butyrolactone: and delta-valerolactone via a 1,3-Michael-Claisen reaction from two 3-carbon units, 1,1-bis-(methylthio)-2-propanone or butanone, and an alpha-methylene lactone.
Aromatic ring synthesis by 1,3-michael-claisen annulation: Application to a trolox analogue and to precocene II
作者:Guy Soiladié、Dominique Boeffel、Jean Maignan
DOI:10.1016/0040-4020(95)01044-0
日期:1996.2
4-dihydro-2-ethoxycarbonyl-6-methoxy-7-hydroxy- benzopyran and Precocene II, were prepared from substituted α-methylene-δ- valerolactone and 1,1-bis-(methylthio)-2-propanone or butanone, via a 1,3-Michael- Claisen annulation.
Studies on the Synthesis of (±)-Stenine: A Combined Intramolecular [4 + 2]-Cycloaddition/Rearrangement Cascade
作者:Albert Padwa、John D. Ginn
DOI:10.1021/jo050515e
日期:2005.6.1
prepared via the reaction of dimethyl(methylthio)sulfonium tetrafluoroborate (DMSTF) with β-alkoxy-γ-dithiane lactams. Thermolysis of these furans resulted in an intramolecularDiels−Alderreaction (IMDAF). The resulting oxa-bridge cycloadducts underwent a subsequent 1,2-methylthio shift to form tricyclic lactams in high yield. Furan 9, annealed to an azepine ring, underwent the IMDAF reaction at or below
Synthesis of Azapolycyclic Systems via the Intramolecular [4 + 2] Cycloaddition Chemistry of 2-(Alkylthio)-5-amidofurans
作者:Albert Padwa、John D. Ginn、Scott K. Bur、Cheryl K. Eidell、Stephen M. Lynch
DOI:10.1021/jo0111816
日期:2002.5.1
prepared via the reaction of dimethyl(methylthio)sulfonium tetrafluoroborate (DMTSF) with beta-alkoxy-gamma-dithiane amides 13-16 and 27-32 in 40-70% yield. Thermolysis of these furans resulted in an intramolecular Diels-Alder reaction (IMDAF). With the exception of 45 and 46, the oxa-bridged cycloadducts could not be isolated but immediately underwent a 1,2-methylthio shift to form bicyclic lactams in 60-100%
Composés benzohétérocycliques, en tant qu'antioxydants
申请人:L'OREAL
公开号:EP0685473A2
公开(公告)日:1995-12-06
La présente demande concerne de nouveaux composés de la famille des benzohétérocycles ainsi que leurs procédés de préparation et les composés intermédiaires obtenus.