Beta-amino acids to piperidinones by Petasis methylenation and acid-induced cyclization.
Ester-imine derivatives of beta-amino acids were methylenated with dimethyltitanocene under microwave irradiation and the resulting enol ethers cyclized with Brönsted 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 1,3-dioxan-4-ones to give tetrahydropyranones.
Adriaenssens
Louis V
LV
WestCHEM Department of Chemistry, University of Glasgow, Glasgow, G12 8QQ, United Kingdom.
Hartley
Richard C
RC
D000143:Acids / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry; D000596:Amino Acids / Q000737:chemistry* / Q000528:radiation effects; D003500:Cyclization; D008745:Methylation; D008872:Microwaves; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry / Q000528:radiation effects; D013237:Stereoisomerism
D000143:Acids; D000596:Amino Acids; D009942:Organometallic Compounds; D010880:Piperidines; D000535:Aluminum