title: Tedarenes A and B: structural and stereochemical analysis of two new strained cyclic diarylheptanoids from the marine sponge Tedania ignis.
abstract: Ring strain causes planar chirality in tedarenes A and B, two cyclic diarylheptanoids isolated from the marine sponge Tedania ignis. In both molecules, the chiral plane is an olefinic system, which is very rare among natural products. In tedarene A (1), interconversion is too fast to allow isolation of the enantiomeric atropisomers but still slow enough to cause coalescence of some (1)H and (13)C NMR signals at room temperature. In tedarene B (2), which also shows stable central and axial chirality, the two planar diastereomers are in slow equilibrium. Tedarene B is the smallest natural product with central, axial, and planar chirality in the same simple molecule. The identification of planar chirality as the difference between its conformational isomers allowed the use of theoretical prediction of the CD spectrum to determine the absolute configuration of the stereogenic carbon C-9 as well as of the biphenyl chiral axis.
authors.affiliation: The NeaNat Group-Dipartimento di Chimica delle Sostanze Naturali, Università di Napoli Federico II, via Domenico Montesano 49, 80131 Napoli, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Costantino
authors.forename: Ernesto
authors.initials: E
authors.lastname: Fattorusso
authors.forename: Alfonso
authors.initials: A
authors.lastname: Mangoni
authors.forename: Cristina
authors.initials: C
authors.lastname: Perinu
authors.forename: Roberta
authors.initials: R
authors.lastname: Teta
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Panza
authors.forename: Angela
authors.initials: A
authors.lastname: Ianaro
mesh_terms: D000818:Animals; D036381:Diarylheptanoids / Q000737:chemistry* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D011161:Porifera / Q000737:chemistry*; D013237:Stereoisomerism; D000097566:Cyclophanes
chemical_list: D036381:Diarylheptanoids; C576625:tedarene A; D000097566:Cyclophanes; C576626:tedarene B