53439-15-9Relevant articles and documents
Anion-Accelerated Aromatic Oxy-Cope Rearrangement in Geranylation/Nerylation of Xanthone: Stereochemical Insights and Synthesis of Fuscaxanthone F
Fujimoto, Yuuki,Takahashi, Kanae,Kobayashi, Ryouma,Fukaya, Haruhiko,Yanai, Hikaru,Matsumoto, Takashi
, p. 1378 - 1383 (2020)
An efficient installation of a 3,7-dimethylocta-2,6-dien-1-yl (geranyl or neryl) side chain at the C(1) position of a xanthone core by utilizing an anion-accelerated aromatic oxy-Cope rearrangement is described. Experiments revealed that this uncommon rearrangement takes place in a stereospecific manner through a chair-like transition-state structure. An application to the syntheses of the natural xanthone fuscaxanthone F, possessing a geranyl side chain, and its neryl analogue is also described.
Scalable synthesis of the aroma compounds d6-β-ionone and d6-β-cyclocitral for use as internal standards in stable isotope dilution assays
Mosaferi, Shabnam,Jelley, Rebecca E.,Fedrizzi, Bruno,Barker, David
supporting information, (2020/12/02)
C13 Norisoprenoids are important aroma compounds in wine, giving positive attributes to the overall wine aroma even when found at very low levels. β-Ionone is considered one of the most important aroma compounds giving violet, woody and raspberry aromas to wine, fruits and vegetables in which it is found. Due to its potent aroma at low levels, precise analytical methods are desired for its quantification. Stable isotope dilution assay (SIDA) is one of the most important of these methods but requires the use of isotopically labelled standards. Herein, we describe the scalable synthesis of d6-β-ionone and d6-β-cyclocitral, another aroma compound with smokey and fruity notes, starting from the relatively inexpensive deuterated starting material d6-acetone.
δ-deuterium isotope effects as probes for transition-state structures of isoprenoid substrates
Choi, Seoung-Ryoung,Breugst, Martin,Houk, Kendall N.,Poulter, C. Dale
supporting information, p. 3572 - 3580 (2014/05/06)
The biosynthetic pathways to isoprenoid compounds involve transfer of the prenyl moiety in allylic diphosphates to electron-rich (nucleophilic) acceptors. The acceptors can be many types of nucleophiles, while the allylic diphosphates only differ in the number of isoprene units and stereochemistry of the double bonds in the hydrocarbon moieties. Because of the wide range of nucleophilicities of naturally occurring acceptors, the mechanism for prenyltransfer reactions may be dissociative or associative with early to late transition states. We have measured δ-secondary kinetic isotope effects operating through four bonds for substitution reactions with dimethylallyl derivatives bearing deuterated methyl groups at the distal (C3) carbon atom in the double bond under dissociative and associative conditions. Computational studies with density functional theory indicate that the magnitudes of the isotope effects correlate with the extent of bond formation between the allylic moiety and the electron-rich acceptor in the transition state for alkylation and provide insights into the structures of the transition states for associative and dissociative alkylation reactions.
