title: Cyclizing Pentapeptides: Mechanism and Application of Dehydrophenylalanine as a Traceless Turn-Inducer.
abstract: Dehydrophenylalanine is used as a traceless turn-inducer in the total synthesis of dichotomin E. Macrocyclization of the monomer is achieved in high yields and selectivity over cyclodimerization under conditions 100 times more concentrated than previously achieved. The enamide facilitates ring closing, and Rh-catalyzed hydrogenation of the unsaturated cyclic peptide results in selective formation of the natural product or its epimer, depending on our choice of phosphine ligand. NMR analysis and molecular modeling revealed that the linear peptide adopts a left-handed α-turn that preorganizes the N- and C-termini toward macrocyclization.
authors.affiliation: Department of Chemistry, University of California , Irvine, California 92697, United States.
authors.forename: Diane N
authors.initials: DN
authors.lastname: Le
authors.affiliation: Department of Chemistry, University of California , Irvine, California 92697, United States.
authors.forename: Jan
authors.initials: J
authors.lastname: Riedel
authors.affiliation: Department of Chemistry, University of California , Irvine, California 92697, United States.
authors.forename: Natalia
authors.initials: N
authors.lastname: Kozlyuk
authors.affiliation: Department of Chemistry, University of California , Irvine, California 92697, United States.|Department of Molecular Biology and Biochemistry, University of California , Irvine, California 92697, United States.
authors.forename: Rachel W
authors.identifier: 0000-0001-9996-7411
authors.initials: RW
authors.lastname: Martin
authors.affiliation: Department of Chemistry, University of California , Irvine, California 92697, United States.
authors.forename: Vy M
authors.identifier: 0000-0002-8099-1048
authors.initials: VM
authors.lastname: Dong