01126nas a2200169   4500008004100000245015100041210006900192520039000261653002500651653001800676653002700694653002300721653003800744100002200782700002600804856012600830       2018                        eng d00aSynthetic studies towards Pseudoxylallemycin B, an antibiotic active against gram-negative bacteria: total synthesis of 3-epi-Pseudoxylallemycin B0 aSynthetic studies towards Pseudoxylallemycin B an antibiotic act3 aIn an attempt towards the total synthesis of Pseudoxylallemycin B, a homo dimeric, N-methylated macrocyclic tetrapeptidic natural product, synthesis of its epimer at position 3 (d-Tyr instead of l-Tyr) is described here. During the course of synthesis we came across a striking yet unusual observation of complete epimerization which led to the formation of 3-epi-Pseudoxylallemycin B.10aCyclic tetrapeptides10aEpimerization10aGram-negative bacteria10aMacrolactamization10aPropyl phosphonic anhydride (T3P)1 aGunjal, Vidya, B.1 aReddy, Shrinivasa, D.  uhttps://library.ncl.res.in/content/synthetic-studies-towards-pseudoxylallemycin-b-antibiotic-active-against-gram-negative