75909-31-8Relevant academic research and scientific papers
Chemistry of Four-Membered Cyclic Nitrones. 1. Synthesis and Thermal Isomerization of 2,3-Dihydroazete 1-Oxides
Pennings, Marcel L. M.,Reinhoudt, David N.
, p. 1816 - 1823 (2007/10/02)
Nitroalkenes (1) react with ynamines (1-aminoacetylenes, 2) to yield nitrocyclobutenes 3 and four-membered cyclic nitrones (2,3-dihydroazete 1-oxides, 5); in one case the open-chain isomer (4) of a four-membered cyclic nitrone was isolated.Nitrones 5 isom
Chemistry of Four-Membered Cyclic Nitrones. 3. Reaction with Nucleophilic Reagents and Stereospecific Conversion into 1-Hydroxyazetidines
Pennings, Marcel L.M.,Reinhoudt, David N.,Harkema, Sybolt,Hummel, Gerrit J. van
, p. 4419 - 4425 (2007/10/02)
Four-membered cyclic nitrones (1) react with a variety of nucleophiles (MeMgI, CN-, OH-, MeO-, and H-) by stereospecific addition to the C=N bond.Reaction of 1a with potassium cyanide and with methylmagnesium iodide yields the 1-hydroxyazetidines 2a and 2b, respectively.Reduction of 1b with lithium aluminum hydride and with sodium borohydride affords the 1-hydroxyazetidine derivatives 3 and 4, respectively.Sodium hydroxide in methanol-water reacts with 1a to give a mixture of two isomeric 5-hydroxyisoxazolidines 5a and 5b, but under similar reaction conditions 1b and 1c rearrange to the oximes 6 and 7.In acetic acid at room temperature 6a cyclizes to the 6H-1,2-oxazin-6-one derivative 8, whereas 6b yields 5-methyl-3,4-diphenylisoxazole (9) after being refluxed in acetic acid, probably by carbon monoxide elimination from the intermediate oxazin-6-one derivative.Reaction of 1a with sodium hydroxide for 2 min gives exclusively the 1-hydroxy-4-methoxyazetidine 13a, whereas prolonged reaction gives the isomeric azetidine 13b together with 5 (mixture of 5a and 5b in a ratio 4:1).Single-crystal X-ray analysis of 13b reveals that all three relatively bulky substituents at C-2, C-3, and C-4 are on the same face of the azetidine ring.Treatment of 13b with acetic acid at room temperature gives the 5-methoxyisoxazolidine 15.The 1-hydroxyazetidines 2-4 are oxidized with yellow mercury(II) oxide to the corresponding four-membered cyclic nitrones 1b, 16 and 17.
OXIDATION OF N-HYDROXYAZETIDINES: A NOVEL SYNTHESIS OF N-ACETOXY β-LACTAMS AND FOUR-MEMBERED CYCLIC NITRONES
Pennings, M. L. M.,Reinhoudt, D. N.
, p. 1003 - 1006 (2007/10/02)
The N-hydroxyazetidines 2 and 3 are prepared starting from 2,3-dihydroazete 1-oxides (1a and 1b) by reduction with sodium borohydride and by reaction with a nucleophile, respectively.The N-hydroxyazetidines 2 and 3 can be oxidized with mercury(II)oxide to
