title: Synthesis of the decalin core of codinaeopsin via an intramolecular Diels-Alder reaction.
abstract: We describe the synthesis of the decalin core of codinaeopsin (1), a tryptophan-polyketide hybrid natural product with promising antimalarial activity (IC50 4.7 μM, against Plasmodium falciparum), via an intramolecular Diels-Alder (IMDA) reaction. A convergent synthesis was developed to prepare the precursors for the IMDA reaction in 10 steps. The exo cycloadducts were derived from thermal, IMDA reactions of the substrates containing a Weinreb amide or ester conjugated dienophile, and the endo adducts were from Lewis acid promoted reactions of the substrates with a formyl group. Both exo and endo products of the IMDA were exclusively isolated and characterized by NMR spectroscopy. One endo cycloadduct was further confirmed with X-ray crystallography. Theoretical calculations reveal the influence of the substituents of the decalin core on the IMDA process.
authors: Department of Chemistry, National Central University, 300 Jhong-Da Rd., Jhong-Li, Taoyuan, Taiwan.
authors: Mani
authors: M
authors: Ramanathan
authors: Chun-Jui
authors: CJ
authors: Tan
authors: Wen-Jung
authors: WJ
authors: Chang
authors: Hui-Hsu Gavin
authors: HH
authors: Tsai
authors: Duen-Ren
authors: DR
authors: Hou
mesh_terms: D060326:Chemistry Techniques, Synthetic; D018942:Macrolides / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity
chemical_list: D018942:Macrolides; D009281:Naphthalenes; C532600:codinaeopsin; C007229:decalin