39637-99-5Relevant articles and documents
Synthesis, Absolute Configurations, and Biological Activities of Floral Scent Compounds from Night-Blooming Araceae
Stamm, Patrick,Etl, Florian,Maia, Artur Campos D.,D?tterl, Stefan,Schulz, Stefan
, p. 5245 - 5254 (2021/04/12)
The uncommon jasmone derivatives dehydrojasmone, isojasmol, and isojasmyl acetate, floral scent compounds from night-blooming Araceae, were synthesized in a scalable synthesis employing conjugate addition with a selenoacetal as the key step. The stereoselective strategy with subsequent enzymatic kinetic resolution allowed determining the absolute configuration of the natural compounds by GC on a chiral phase. The homoterpene (E)-4,8-dimethyl-1,3,7-nonatrien-5-yl acetate, another uncommon scent compound, was obtained by α-regioselective aldehyde prenylation. The biological activities of dehydrojasmone and isojasmol were investigated in field assays, showing that these unique volatiles are able to selectively attract specific cyclocephaline scarab beetle pollinators.
Studies toward norzoanthamine: Ireland–Claisen rearrangements of α,β-unsaturated esters in a stereocontrolled synthesis of trans-fused 2-cyclohexen-1-ones
Gladen, Paul T.,Patnaik, Samarjit,Williams, David R.
, (2021/07/28)
The enantiocontrolled preparation of the trans-fused ABC ring system of norzoanthamine is described. The synthesis strategy has incorporated studies of Ireland–Claisen rearrangements of esters derived from 3,3-dimethylacrylic acid. Stereocontrol results from competing chair- and boat-like transition states. Introduction of a nitroalkene by application of a modified Henry reaction facilitates an intramolecular Diels–Alder cycloaddition for an effective and simple transformation to the desired conjugated decalone. A fully functionalized AB ring system leads to the cyclization of the trans-fused cyclohexenone to complete the ABC system via ring-closing metathesis.
Photochemical Electrocyclization of Poly(phenylacetylene)s: Unwinding Helices to Elucidate their 3D Structure in Solution
Rey-Tarrío, Francisco,Rodríguez, Rafael,Qui?oá, Emilio,Riguera, Ricardo,Freire, Félix
supporting information, p. 8095 - 8103 (2021/02/26)
Photochemical electrocyclization of poly(phenylacetylene)s (PPAs) is used for the structural elucidation of a polyene backbone. This method not only allows classification of PPAs in cis-cisoidal (ω11>90°), but also approximating ω1. A PPA solution is illuminated with visible light and monitoring the photochemical electrocyclization of the PPA helix by measuring the ECD spectra at different times. PPAs with a cis-cisoidal structure show a reduction of the ECD signal of at least 50 % before 30 min of irradiation, while cis-transoidal helices need much longer time because the transoidal bond must be isomerized. The different cis-cisoidal and cis-transoidal helices require different times to decrease their ECD signal by 50 % (t1/2), depending on the degree of compression or stretching of the helix, establishing a relationship between the secondary structure adopted by PPA (ω1) and the time required to lose the ECD vinylic signal by light irradiation.
