1676-75-1Relevant articles and documents
Selective cleavage of tert-butyl esters in the presence of tert-butyl ethers. Application to the synthesis of tert-butoxy amino acids
Trzeciak, Arnold,Bannwarth, Willi
, p. 1433 - 1434 (1996)
We report on the selective cleavage of tert-butyl esters in the presence of tert-butyl ether groups by using trimethylsilyl triflate. The method is especially useful for the synthesis of tert-butyl ethers of N-protected hydroxy amino acids which are valuable building blocks for peptide synthesis.
Biosynthesis of Hyalodendrin and Didethiobis(methylthio)hyalodendrin, Sulphur-containing 2,5-Dioxopiperazines of the 3S,6S Series
Boente, Maria I. Pita,Kirby, Gordon W.,Patrick, Graham L.,Robins, David J.
, p. 1283 - 1290 (2007/10/02)
cyclo-(L-Phe-L-Ser) 8, a known biosynthetic precursor of the (3R,6R)-epidithiodioxopiperazine gliotoxin 4, was efficiently incorporated (42percent), in Hyalodendron sp. (FSC-601) cultures, into the 3S,6S metabolite didethiobis(methylthio)hyalodendrin (DBH) 7 without significant change in the 3H:14C ratio.None of the three diasteromers of cyclo-(L-Phe-L-Ser) was incorporated into DBH to any significant extent.The 13C label from cyclo-(L-Phe-L-Ser) was located, in the expected site, in DBH by 13C NMR spectroscopy.Gliotoxin derived in Gliocladium virens from the doubly labelled precursor 8 was degraded to locate, in similar manner, the 14C label.The N-methyl derivative 16 of cyclo-(L-Phe-L-Ser) was not incorporated detectably into either gliotoxin or DBH.Radioactivity from the doubly labelled, linear dipeptides 17 and 18, possible precursors for the cyclodipeptide 8, was incorporated with moderate efficiency into gliotoxin.However, the 3H:14C ratios for the dipeptides and the derived gliotoxin differd substantially, indicating that the peptides had undergone cleavage in the fungus before incorporation.
