Stereoselektive Synthese von Benzomorphan-Derivaten an perpivaloylierter Galactose als chiralem Auxiliar

Stereoselective Synthesis of Enantiomerically Pure Piperidine Derivatives by N-Galactosylation of Pyridones.

Stereoselective desymmetrization of 4-pyridone has been achieved through selective N-galactosylation, activation of the N-(galactosyl)pyridone by O-silylation and immediate addition of Grignard compounds. Chiral piperidine derivatives, e.g. (S)-(+)-coniine and (5S,9S)-(+)-indolozidine 167B, were synthesised in enantiomerically pure form using these highly regio- and stereoselective reactions. After N-galactosylation of 2-pyridone and O-silylation of the N-galactosyl-2-pyridone, addition of a Grignard compound proceeded with high 1,4-regioselectivity and complete diastereoselectivity, to furnish 4-substituted 5,6-dehydro-2-piperidones. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Ger…

Stereoselective Synthesis of Enantiomerically Pure Piperidine Derivatives byN-Galactosylation of Pyridones

Stereoselective desymmetrization of 4-pyridone has been achieved through selective N-galactosylation, activation of the N-(galactosyl)pyridone by O-silylation and immediate addition of Grignard compounds. Chiral piperidine derivatives, e.g. (S)-(+)-coniine and (5S,9S)-(+)-indolozidine 167B, were synthesised in enantiomerically pure form using these highly regio- and stereoselective reactions. After N-galactosylation of 2-pyridone and O-silylation of the N-galactosyl-2-pyridone, addition of a Grignard compound proceeded with high 1,4-regioselectivity and complete diastereoselectivity, to furnish 4-substituted 5,6-dehydro-2-piperidones. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Ger…

Stereoselective synthesis of benzomorphan derivatives with perpivaloylated galactose as the chiral auxiliary.

ChemInform Abstract: Stereoselective Synthesis of 3-Substituted and 3,4-Disubstituted Piperidine and Piperidin-2-one Derivatives.

The reaction of various electrophiles with N-galactosylpyridinone derivatives proceeds with moderate to high diastereoselectivity to afford the target compounds.

ChemInform Abstract: Regio- and Stereoselective Addition of Grignard Reagents to N-Galactosyl-2-pyridone: Synthesis of 4-Substituted 5,6-Didehydro-2-piperidinones.

Stereoselective Synthesis of 3-Substituted and 3,4-Disubstituted Piperidine und Piperidin-2-one Derivatives

The stereoselective synthesis of 3-substituted and 3,4-disubstituted piperidine and piperidin-2-one derivatives was achieved starting from 2-pyridone. After N-galactosylation and subsequent O-silylation, nucleophilic addition of organometallic reagents proceeded with high regio- and stereoselectivity at 4-position. Substituents at position 3 were stereoselectively introduced by reaction of electrophiles with amide enolates of the N-galactosyl-2-piperidones.