Catalytic Asymmetric Synthesis of the Central Tryptophan Residue of Celogentin C
作者:Steven L. Castle、G. S. C. Srikanth
DOI:10.1021/ol035236x
日期:2003.10.1
[reaction: see text] Chiral phase-transfer catalyst 5 containing an electron-deficient trifluorobenzyl moiety promoted the alkylation of glycine derivative 6 with propargyl bromide 7a in good yield and excellent ee. The resulting propargyl glycine 8 was converted to 14, the central tryptophan residue of Celogentin C, in two steps, with the Pd-catalyzed heteroannulation as the key transformation. This
Total Synthesis of the Antimitotic Bicyclic Peptide Celogentin C
作者:Bing Ma、Biplab Banerjee、Dmitry N. Litvinov、Liwen He、Steven L. Castle
DOI:10.1021/ja909870g
日期:2010.1.27
An account of the totalsynthesis of celogentin C is presented. A right-to-left synthetic approach to this bicyclic octapeptide was unsuccessful due to an inability to elaborate derivatives of the right-hand ring. In the course of these efforts, it was discovered that the mild Braslau modification of the McFadyen-Stevens reaction offers a useful method of reducing recalcitrant esters to aldehydes.