Radical-mediated dehydrative preparation of cyclic imides using (NH₄)₂S₂O₈–DMSO: application to the synthesis of vernakalant

• Dnyaneshwar N. Garad,
• Subhash D. Tanpure and
• Santosh B. Mhaske

Beilstein J. Org. Chem. 2015, 11, 1008–1016, doi:10.3762/bjoc.11.113

• polymers. Migrastatin, lamprolobine, julocrotine, cladoniamide A, palasimide and salfredin C-1 are few of the important natural products having the imide motif [1][2][3][4]. Imides have been extensively used in the synthesis of several bioactive natural products [5][6][7][8][9][10][11][12]. Various drugs

Synthesis of antibacterial 1,3-diyne-linked peptoids from an Ugi-4CR/Glaser coupling approach

• Martin C. N. Brauer,
• Ricardo A. W. Neves Filho,
• Bernhard Westermann,
• Ramona Heinke and
• Ludger A. Wessjohann

Beilstein J. Org. Chem. 2015, 11, 25–30, doi:10.3762/bjoc.11.4

• , this reaction has been used in the synthesis of bioactive peptides and pseudopeptides, e.g., tubulysin mimetics [13], julocrotine derivatives [14], architecturally complex peptoid macrocycles [15][16], building blocks for diversity-oriented synthesis [17], and heterocyclic compounds [18]. Complex

Synthesis of (−)-julocrotine and a diversity oriented Ugi-approach to analogues and probes

• Ricardo A. W. Neves Filho,
• Bernhard Westermann and
• Ludger A. Wessjohann

Beilstein J. Org. Chem. 2011, 7, 1504–1507, doi:10.3762/bjoc.7.175

• 10.3762/bjoc.7.175 Abstract An improved total synthesis of (−)-julocrotine in three steps from Cbz-glutamine, in 51% overall yield, is presented. To demonstrate the potential of the heterocyclic moiety for diversity oriented synthesis, a series of (−)-julocrotine analogues was synthesized by employing the

• heterocyclic precursor as an amino input in Ugi four-component reactions (Ugi-4CR) [1]. Keywords: diversity oriented synthesis; julocrotine; leishmania; Mitsunobu reaction; Ugi reaction; Introduction Julocrotine (1) is a natural glutarimide alkaloid isolated from several plants of the genus Croton [2][3][4

• ]. In addition, the glutarimide motif can be considered as a privileged structure. Compounds with this pharmacophore often exhibit a wide range of biological properties including anti-inflammatory [10], antitumor [11][12], and anticonvulsive properties [13]. Because of the low yields of julocrotine