Heterocyclic compounds, pharmaceutical compositions comprising same, and methods for inhibiting &bgr;-amyloid peptide release and/or its synthesis by use of such compounds
作者:Zhengshuang Xu、Tao Ye、Qi Ren、Lu Dai、Hui Zhang、Wenfei Tan
DOI:10.1055/s-2008-1078270
日期:——
The stereocontrolled total synthesis of largazole was accomplished, unambiguously confirming its structure. Key steps included the use of the Nagao thiazolidinethione auxiliary for a diastereoselective acetate aldol reaction, thiazoline-thiazole formation, and macrolactamization by use of the Mukaiyama reagent.
Verfahren zur elektrophilen Substitution von Thiazolidinen oder Oxazolidinen
申请人:Consortium für elektrochemische Industrie GmbH
公开号:EP1452529A1
公开(公告)日:2004-09-01
Die Erfindung betrifft ein Verfahren zur Herstellung von α-funktionalisierten in 4-Position Oxycarbonyl-funktionalisierten Thiazolidinen oder Oxazolidinen durch Zugabe einer Base zu einer Reaktionsmischung enthaltend ein Oxycarbonyl-funktionalisiertes Thiazolidin oder Oxazolidin und ein Elektrophil bei einer Temperatur von größer -40°C.
Separate condensation of other chiral (8 and 13) and racemic (18) amino thiols as auxiliary with rac-4, (4S)-4, or (4R)-4 is accompanied by an in situ crystallization-induced dynamic resolution, whereby one distereomer of thiazole template selectively precipitates and can be isolated by simple filtration in 76−82% yield with dr > 99. The thiazole species isolated from this process resulted from an amino
Full details of the concise and convergent synthesis (eight steps, 19% overall yield), its extension to the preparation of a series of key analogues, and the molecular target and pharmacophore of largazole are described. Central to the synthesis of largazole is a macrocyclization reaction for formation of the strained 16-membered depsipeptide core followed by an olefin cross-metathesis reaction for
Enantioselective Synthesis of 2-alkyl substituted cysteines
作者:Gerald Pattenden、Stephen M. Thom、Martin F. Jones
DOI:10.1016/s0040-4020(01)86313-4
日期:1993.3
Treatment of the N-formyl derivative of the thiazolidine adduct derived from (R-cysteine methyl ester hydrochloride and pivalaldehyde, with LDA-DMPU at −90°C, followed by reaction with iodomethane produces the corresponding methylated thiazolidine containing the methyl and t-butyl groups virtually exclusively anti- to one another. Hydrolysis in the presence of 5M HCl then affords (R-2-methylcysteine