The oxidative homocouplings of lithium enolates of (4S)-3-(3-arylpropanoyl)-4-isopropyl-2-oxazolidinones and (4R,5S)-1-(3-arylpropanoyl)-3,4-dimethyl-5-phenyl-2-imidazolidinones gave the corresponding R,R-dimers stereoselectively with TiCl4, PhI(OAc)2, or CuCl2 as an oxidant. The stereoselectivity can be explained by a radical coupling mechanism. Optically active dibenzylbutyrolactone lignans, such as (−)-hinokinin and (−)-dimethylmatairesinol, and dibenzylbutanediol lignans, such as (−)-dihydrocubebin and (−)-dimethylsecoisolariciresinol, were synthesized from the major R,R-dimers. The oxidative coupling of (4R,5S)-1-(3-arylpropanoyl)-3,4-dimethyl-5-phenyl-2-imidazolidinones with LDA−I2 gave R,S-dimers mainly, and this result can be explained by an SN2 mechanism.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Abstract Addition der aus den α‐Bromthioethern (Ia) und (Ib) thermisch generierten Schwefelylide (II) an die Acrylsäure‐Derivate (III) liefert ein Gemisch der regioisomeren Tetrahydrothiophene (IV) und (V).
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
