78602-09-2Relevant academic research and scientific papers
Chemistry of Four-Membered Cyclic Nitrones. 4. Reaction with Electrophilic Reagents and Conversion into β-Lactam Derivatives
Pennings, Marcel L. M.,Reinhoudt, David N.,Harkema, Sybolt,van Hummel, Gerrit J.
, p. 486 - 491 (2007/10/02)
The conversion of the four-membered cyclic nitrone 1a into a β-lactam has been investigated by using several electrophilic reagents.With methanesulfonyl chloride or with acetic acid, 1a reacts to give the oxime 2.In acetic acid this oxime undergoes cycliz
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.
CHEMISTRY OF 4-MEMBERED CYCLIC NITRONES (2,3-DIHYDROAZETE 1-OXIDES); A NOVEL ONE-STEP SYNTHESIS OF N-ACETOXY β-LACTAMS
Pennings, M. L. M.,Reinhoudt, D. N.
, p. 1153 - 1156 (2007/10/02)
2,3-Dihydroazete 1-oxide 1 reacts at room temperature with base, acid and lead tetraacetate to give the 5-hydroxyisoxazolidines 4a and 4b, the 6H-1,2-oxazin-6-one 7 and the N-acetoxy β-lactam 8, respectively; the reaction with lead tetraacetate represents
