title: Metal-free decarboxylative hetero-Diels–Alder synthesis of 3-hydroxypyridines: a rapid access to N-fused bicyclic hydroxypiperidine scaffolds.
abstract: A complete experimental and theoretical study of the thermally controlled metal-free decarboxylative hetero-Diels–Alder (HDA) reaction of 5-alkoxyoxazoles with acrylic acid is reported. This strategy offers a new entry to valuable 2,6-difunctionalized 3-hydroxypyridines from readily available 2- and 4-disubstituted 5-alkoxyoxazoles. The reaction conditions proved compatible with, among others, ketone, amide, ester, ether, and nitrile groups. The broad functional group tolerance of the protocol allows a rapid and versatile access to both hydroxyindolizidine and hydroxyquinolizidine derivatives via a pyridine dearomatization strategy.
authors.forename: Laurie-Anne
authors.initials: LA
authors.lastname: Jouanno
authors.forename: Vincent
authors.initials: V
authors.lastname: Di Mascio
authors.forename: Vincent
authors.initials: V
authors.lastname: Tognetti
authors.forename: Laurent
authors.initials: L
authors.lastname: Joubert
authors.forename: Cyrille
authors.initials: C
authors.lastname: Sabot
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Renard
mesh_terms: D061565:Cycloaddition Reaction; D054836:Indolizidines / Q000138:chemical synthesis* / Q000737:chemistry; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D011743:Pyrimidines / Q000737:chemistry*; D054837:Quinolizidines / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D054836:Indolizidines; D008670:Metals; D010880:Piperidines; D011725:Pyridines; D011743:Pyrimidines; D054837:Quinolizidines; C062320:N-hydroxypiperidine; C023500:3-hydroxypyridine