A practical asymmetric synthesis of 2,6-cis-disubstituted piperidines
摘要:
A highly diastereoselective intramolecular Mannich reaction involving enantiopure alpha-methylamine 7 and achiral aldehydes is employed to prepare enantiomerically pure 2,6-cis-disubstituted piperidines. This methodology provides an efficient and selective route to 2,6-cis-disubstituted piperidines, 2,6-cis-disubstituted 4-piperidones and 2,6-cis-disubstituted 4-piperidinols. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
A practical asymmetric synthesis of 2,6-cis-disubstituted piperidines
摘要:
A highly diastereoselective intramolecular Mannich reaction involving enantiopure alpha-methylamine 7 and achiral aldehydes is employed to prepare enantiomerically pure 2,6-cis-disubstituted piperidines. This methodology provides an efficient and selective route to 2,6-cis-disubstituted piperidines, 2,6-cis-disubstituted 4-piperidones and 2,6-cis-disubstituted 4-piperidinols. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.
β-Amino Acids to Piperidinones by Petasis Methylenation and Acid-Induced Cyclization
作者:Louis V. Adriaenssens、Richard C. Hartley
DOI:10.1021/jo7019948
日期:2007.12.1
[GRAPHICS]Ester-imine derivatives of beta-amino acids were methylenated with dimethyltitanocene under microwave irradiation and the resulting enol ethers cyclized with Bronsted acid or triisopropylaluminium to give 2,6-syn-disubstituted piperidinones in good yield and diastereoselectivity. The method is analogous to the Petasis-Ferrier rearrangement of 1,3dioxan-4-ones to give tetrahydropyranones.