5164-37-4Relevant academic research and scientific papers
A novel tandem [2 + 2] cycloaddition-Dieckmann condensation with ynolate anions. Efficient synthesis of substituted cycloalkenones and naphthalenes via formal [n + 1] cycloaddition
Shindo,Sato,Shishido
, p. 7818 - 7824 (2007/10/03)
A novel tandem [2 + 2] cycloaddition-Dieckmann condensation via ynolate anions is described. Ynolate anions are useful for the formation of reactive β-lactone enolates via a pathway not involving the enolization of the corresponding β-lactones. The [2 + 2] cycloaddition of ynolate anions with δ- or σ-keto esters, followed by Dieckmann condensation, gives bicyclic β-lactones, which are easily decarboxylated to produce synthetically useful 2,3-disubstituted cyclopentenones and cyclohexenones in one pot. This tandem reaction was applied to a novel, one-pot synthesis of highly substituted naphthalenes.
A new method for the preparation of Michael adducts and cyclic enones using lithium chloride-hexamethylphosphoramide system
Ozaki,Kubo,Okamura,Kim
, p. 734 - 737 (2007/10/02)
A new procedure using lithium chloride in hexamethylphosphoramide was found to be useful for the synthesis of Michael-type adducts and cyclic enones. Selectivity for the two products could be controlled by altering the reaction temperature employed. The urea-type solvents were also examined instead of hexamethylphosphoramide.
Allylation with substituted vinylthionium ions from SnCl4 ionisation of 1,3- and 3,3-bis(alkyl/phenylthio)propenes
Hunter,Michael,Walter
, p. 9377 - 9398 (2007/10/02)
α- and γ-substituted vinylthionium ions from SnCl4 ionisation of a range of substituted 1,3- and 3,3-bis(alkyl/phenylthio)propenes allylate enol silyl ethers in good yield. Levels of regioselectivity are sterically dependent and in the case of
A Method for the Cyclic Enone Synthesis Using Lithium Chloride-Hexamethylphosphoramide System
Ozaki, Yutaka,Kubo, Ayako,Kim, Sang-Won
, p. 993 - 994 (2007/10/02)
Cyclic enones were obtained from the reactions of β-keto esters with acyclic α,β-unsaturated ketones by using lithium chloride in hexamethylphosphoramide.The products were brought via the Michael addition, decarboxylation, and the aldol condensation.
Alkylation of enol silyl ethers with vinylthionium ions generated from 1,1- and 1,3-bis(phenylthio)propenes
Hunter, Roger,Michael, Joseph P.,Walter, Daryl S.
, p. 5413 - 5416 (2007/10/02)
Vinylthionium ions generated from 1,1- and 1,3-bis-(phenylthio) propenes alkylate enol silyl ethers regioselectively under mild reaction conditions with tin tetrachloride.
Organotin Triflate as Practical Catalyst for Michael Addition of Enol Silyl Ethers
Sato, Tsuneo,Wakahara, Yoshiyuki,Otera, Junzo,Nozaki, Hitosi
, p. 9773 - 9782 (2007/10/02)
Dibutyltin bis(triflate) is a mild Lewis acid which catalyzes clean Michael addition of enol silyl ethers.The new catalyst allows to employ various labile acceptors such as methyl vinyl ketone and 2-cyclopentenone which do not undergo smooth reaction with
Organotin triflates as functional Lewis acids. A new entry to simple and efficient Robinson annulation
Sato, Tsuneo,Wakahara, Yoshiyuki,Otera, Junzo,Nozaki, Hitosi
, p. 1581 - 1584 (2007/10/02)
An efficient Robinson annulation has been established through the Michael addition of enol silyl ethers to α-enones catalyzed by dibutyltinbis(triflate) followed by the MeONa-mediated intramolecular aldol condensation of the adducts.
REGIOSELECTIVE HYDRATION OF ALKYNONES BY PALLADIUM CATALYSIS
Imi, Katsuharu,Imai, Kumiko,Utimoto, Kiitiro
, p. 3127 - 3130 (2007/10/02)
Diketones are regioselectively prepared from alkynyl ketones under mild conditions by palladium catalysis; 5-heptyn-2-one and 2-(2-nonynyl)cyclohexanone give 1,4-diketones whereas 2-(2-heptynyl)cyclopentanone and 5,6-didehydroprostaglandin E2 methyl ester afford 1,5-diketones.
