Diels-Alder reactions of N-acyl-2-alkyl(aryl)-5-vinyl-2,3-dihydro-4-pyridones.
Readily available N-acyl-5-vinyl-2,3-dihydro-4-pyridones undergo Diels-Alder cyclization with various dienophiles to afford novel octahydroquinolines containing synthetically useful functionality. With dihydropyridone 5 and cis-disubstituted dienophiles, the resulting cycloadducts were obtained as single diastereomers in good to excellent yield. The corresponding reaction of 5 with methyl acrylate, acrylonitrile, and phenyl vinyl sulfone showed modest preference for the endo adducts. The effect of the dihydropyridone C-2 and C-4 substituents on the degree of diastereofacial control was examined. By using this methodology, the core decahydroquinoline skeleton of gephyrotoxin was prepared in a stereocontrolled fashion. Interesting reactivity was observed with certain dienophiles leading to ring-opening of the initially formed cycloadducts. This tandem reaction provides a route to uniquely substituted beta-aminoketones, alcohols, and unnatural amino acids.
Comins
Daniel L
DL
Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA. daniel_comins@ncsu.edu
Kuethe
Jeffrey T
JT
Miller
Teresa M
TM
Février
Florence C
FC
Brooks
Clinton A
CA
D000438:Alcohols / Q000138:chemical synthesis*; D000596:Amino Acids / Q000138:chemical synthesis*; D020650:Combinatorial Chemistry Techniques; D003500:Cyclization; D007659:Ketones / Q000138:chemical synthesis*; D015394:Molecular Structure; D011728:Pyridones / Q000737:chemistry*; D013237:Stereoisomerism
D000438:Alcohols; D000596:Amino Acids; D007659:Ketones; D011728:Pyridones