Studies of Azetidin-2-one as a Reactive Enolate Synthon of β-Alanine for Condensations with Aldehydes and Ketones.
Studies describe formation of the lithium enolate of N-(4-methoxybenzyloxy)azetidin-2-one (1) and characterization of representative aldol reactions with aldehydes and ketones. Diastereoselectivity features the production of anti-aldol adducts from α,β-unsaturated ketones and α-branched aliphatic aldehydes. The stereoselectivity is rationalized via closed, six-membered transition-state arrangements leading to the formation of Felkin-Anh and anti-Felkin products. Examples illustrate the direct incorporation of monocyclic β-lactams into a variety of molecular architectures. The utility of 1 as an enolate synthon of homoglycine (β-alanine) is illustrated by the efficient synthesis of novel β-amino acid derivatives, including complex 4-hydroxy-2-pyridinones.
Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
David R
DR
Williams
Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
Andrew F
AF
Donnell
Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
David C
DC
Kammler
Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
Sarah A
SA
Ward
Department of Chemistry, Indiana University , Bloomington, Indiana 47405, United States.
Levin
L
Taylor
D000447:Aldehydes / Q000737:chemistry*; D001384:Azetidines / Q000737:chemistry*; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D007659:Ketones / Q000737:chemistry*; D013058:Mass Spectrometry; D066244:Proton Magnetic Resonance Spectroscopy; D013237:Stereoisomerism; D015091:beta-Alanine / Q000737:chemistry*
C116379:2-azetidinone; D000447:Aldehydes; D001384:Azetidines; D007659:Ketones; D015091:beta-Alanine