A remarkable proline-catalyzed method for the construction of biologically interesting oxygen-bridged tricyclic ketal skeletons was uncovered by starting from a variety of readily available cyclic 1,3-diketones and either 1,4- or 1,5-dicarbonyl substrates. The approach, which mimics a biosynthetic Knoevenagelcondensation/[4+2] cycloaddition sequence, establishes a viable synthetic strategy for the
A Samarium(II)-Mediated, Stereoselective Cyclization for the Synthesis of Azaspirocycles
作者:Giuditta Guazzelli、Lorna A. Duffy、David J. Procter
DOI:10.1021/ol8017209
日期:2008.10.2
Unsaturated keto-lactams undergo sequential conjugate reduction-aldol cyclization on treatment with SmI 2 to give syn-spirocyclic pyrrolidinones and piperidinones containing vicinal, fully substituted stereocenters with complete diastereocontrol. The substituent on nitrogen and the lactam ring size have a marked impact on the efficiency of the spirocyclization.
Addition of nitrile oxides to olefins. Synthesis of dihydrojasmone and starting material for prostanoids. A novel route to pyrroles
作者:S.K. Mukerji、K.K. Sharma、K.B.G. Torssell
DOI:10.1016/s0040-4020(01)91944-1
日期:——
Routes to dihydrojasmone and γ-keto-aldehydes and an alternative procedure for a key intermediate in our prostaglandin synthesis are described. 2-Isoxazolines are useful intermediates for a preparation of a variety of classes of compounds. A novel route to pyrroles is established.
Preparation of α-substituted acroleins via the reaction of aldehyde or the corresponding ozonide with dihalomethane and diethylamine
作者:Yung-Son Hon、Feng-Jon Chang、Ling Lu、Wei-Chi Lin
DOI:10.1016/s0040-4020(98)00216-6
日期:1998.5
Treatment of aldehydes or the corresponding ozonides with a mixture of dibromomethane and diethylamine afforded α-substituted acroleins in modest to good yields. The β-carbon of the acrolein (nc, n = 1–16) derived from dibromomethane. Functional groups, such as ketone, hydroxy, acetoxy, bromide, iodide, ester are compatible with this reaction condition. The relative rates and yields of this transformation
Disclosed herein is a method comprising administering a compound to a mammal suffering from an inflammatory bowel disease for the treatment of said disease, said compound having a structure according to Formula I
wherein X, Y, B, R
2
, R
3
, R
4
, R
5
, R
6
and n have the meanings found herein.