(2S,4R)- and (2S,4S)-perfluoro-tert-butyl 4-hydroxyproline were synthesized (as Fmoc-, Boc-, and free amino acids) in 2-5 steps. The key step of each synthesis was a Mitsunobu reaction with perfluoro-tert-butanol, which incorporated a perfluoro-tert-butyl group, with nine chemically equivalent fluorines. Both amino acids were incorporated in model α-helical and polyproline helix peptides. Each ...

chamomile (matricaria chamomilla l.) is one of the most important medicinal plants in iran. the main objective of this study was to determine the effects of organic nutrients on the yield and oil content of chamomile. the experiment was conducted in the spring of 2010. the treatment groups consisted of vermicompost (0, 5, 10, 15 and 20 tons/ha) and the aminol forte sprays (no spraying or contro...

Chiral N-protected α-amino aryl-ketones are one of the useful precursors used in the synthesis of various biologically active compounds and can be constructed via Friedel-Crafts acylation of N-protected α-amino acids. One of the drawbacks of this reaction is the utilization of toxic, corrosive and moisture-sensitive acylating reagents. In peptide construction via amide bond formation, N-hydroxy...