144786-60-7Relevant academic research and scientific papers
Stereoselective Csp3-Csp2 Bond-Forming Reactions by Transition-Metal-Free Reductive Coupling of Cyclic Tosylhydrazones with Boronic Acids
Plaza, Manuel,Pérez-Aguilar, M. Carmen,Valdés, Carlos
, p. 6253 - 6257 (2016)
The reactions between alkenylboronic acids and tosylhydrazones derived from substituted cyclohexanones lead to the construction of disubstituted cyclohexanes with total regio- and stereoselectivity. In these transition-metal-free processes, a Csp3-Csp2 and Csp3-H bond are formed on the same carbon atom. The stereoselective reaction is general for 2-, 3-, and 4-substituted cyclohexanone tosylhydrazones, as well as for 2-substituted cyclopentanones. However, no stereoselectivity is observed for acyclic derivatives. DFT computational modeling suggests that the stereoselectivity of the reaction is determined by the approach of the boronic acid to the diazocyclohexane on its most stable chair conformation through an equatorial trajectory.
Structure analyses of menthone- and isomenthone-tosylhydrazones, C17H26N2O2S
Mullica, D.F.,Garner, C.M.,Prince, M.E.,Mossman, B.C.,Sappenfield, E.L.
, p. 515 - 522 (1992)
The crystal and molecular structures of two configurational isomers of the title compound have been determined by three-dimensional, single-crystal X-ray diffractometry.Both (2S,5R)- and (2R,5R)-4-methylbenzenesulfonic acid-5-methyl-2-(1-methylethyl)cycl
Aromatic annulation on the p-menthane monoterpenes: Enantiospecific synthesis of the trans and cis isomers of calamenene and 8-hydroxycalamenene
Serra, Stefano,Fuganti, Claudio
, p. 4769 - 4772 (2007/10/03)
A new enantiospecific route to sesquiterpenes of the calamenene family is described. The synthetic pathway starts from easily available 3-oxygenated-p-menthane monoterpenes and affords the title compounds by a homologation-benzannulation sequence. The trans and cis isomers of the natural compounds calamenene and 8-hydroxycalamenene were obtained in enantiopure form starting from (-)-menthone and (+)-isomenthone, respectively.
The Epimerization of α-Chiral Hydrazones: Menthonetosylhydrazone.
Garner, Charles M.,Mossman, Brett C.,Prince, Mark E.
, p. 4273 - 4276 (2007/10/02)
The first preparation of (-)-menthonetosylhydrazone (2) in diastereomerically pure form is reported.Kinetic studies show that 2 is far more susceptible to acid-catalyzed epimerization (ca. 150x) than is the parent ketone, (-)-menthone (1), a relationship which has not been generally recognized.Conversion of 2 to 1-menthenyllithium (3) using excess butyllithium occurs without detectable epimerization, as determined by analysis of the 1-iodomenthene 5 obtained by treatment of 3 with iodine in-situ.
Hydrogen Participation vs. Elimination. The Role and Fate of Neighboring Hydrogen in Solvolysis of Neomenthyl Tosylate
Hirsl-Starcevic, Sanja,Majerski, Zdenko,Sunko, Dionis E.
, p. 3388 - 3393 (2007/10/02)
Product composition and α-d1 and β-d3 isotope effects in the solvolysis of neomenthyl tosylate (8-OTs) were determined in 70 percent aqueous trifluoroethanol and 70 percent aqueous ethanol.Both trifluoroethanolysis and ethanolysis gave 1-2 percent neomenthol (97percent d3), 12-13percent cis-4-menthanol (100percent d3), 2-3percent trans-4-menthanol (100percent d3), 66-70percent 3-p-menthene (83percent d3 and 17percent d2), and 5-9percent 4,8-p-menthene (97percent d3), respectively.These results and the high value of the β-d3 isotope effect (kH/kD=2.45) were interpreted in terms of rate-determining hydride shift followed by elimination which accounts for 75percent of all products.In 85percent of the elimination productsthe migrating hydrogen (deuterium) is not the one being eliminated.
