An original and rapid domino reaction for access to oxazolidin-4-ones is presented. Simply by heating α-bromoamido alcohol in the presence of KNaCO3 and water with readily prepared Michael acceptors, an unprecedented molecular rearrangement is generated. This new methodology enables the hitherto unreported synthesis of functionalized oxazolidin-4-ones. The process was proved to be compatible with a wide variety of substrates, and high regioselectivities were achieved.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.orglett.6b00851 | DOI Listing |
Org Biomol Chem
May 2017
St. Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St. Petersburg, 199034 Russia.
The cycloaddition of arenecarbaldehydes and α,α,α-trifluoroacetophenones with gem-difluoro-substituted azomethine ylides, generated from N-benzhydrylideneamines and difluorocarbene, occurs regioselectively to give, after hydrolysis, oxazolidin-4-ones. The primary cycloadducts of trifluoroacetophenones, 4,4-difluoro-5-trifluoromethyloxazolidine derivatives, are sufficiently stable to be isolated in reasonable to excellent yields. The results of correlation analysis and DFT calculations reveal a non-pericyclic step-wise mechanism of the reaction.
View Article and Find Full Text PDFOrg Lett
May 2016
Normandie Université, UNIHAVRE, URCOM, 76600 Le Havre 25, Rue Philipe Lebon, BP 540, F-76600 Le Havre, France.
Chemistry
July 2015
EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, KY16 9ST (UK).
Carbohydr Res
February 2015
Department of Organic Chemistry, University of Debrecen, POB 20, H-4010 Debrecen, Hungary. Electronic address:
Reactions of O-peracetylated (α-D-galacto-heptulopyranosyl bromide)onamide and O-perbenzoylated (α-D-gluco-heptulopyranosyl bromide)onamide with ketones in the presence of silver(I) salt promoters gave the corresponding O-peracylated 1',5'-anhydro-D-glycitol-spiro-[1',5]-4-imino-2,2-disubstituted-1,3-dioxolanes. The D-galacto configured starting compounds furnished both spiro epimers, while the D-gluco counterparts yielded only configurationally inverted products. Under acidic conditions, O-perbenzoylated α-D-gluco-heptulopyranosonamide and ketones yielded the protected 1',5'-anhydro-D-glucitol-spiro-[1',5]-2,2-disubstituted-oxazolidin-4-ones, which were O-debenzoylated by the Zemplén protocol.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!