The synthesis of different diketomorpholines via N-acyl-3,4-dihydro-2 H-1,4-oxazine-3-carboxylic acids is reported in this article. The key intermediates were prepared using a convenient solid-phase synthesis starting from polymer-supported Ser( tBu)-OH. After subsequent sulfonylation with 4-nitrobenzenesulfonyl chloride (4-Nos-Cl), alkylation with an α-bromoketone, cleavage of the 4-Nos group and acylation with an α-halocarboxylic acids, acid-mediated cleavage from the resin yielded dihydrooxazine-3-carboxylic acids in high crude purities. Depending on the reaction conditions, exposure to base resulted in cyclization to either oxazino[3,4- c][1,4]oxazine-diones or 3-methylidenemorpholine-2,5-diones. Further reaction with triethylsilane-trifluoroacetic acid (TES/TFA) led to olefin reduction, in the case of oxazino[3,4- c][1,4]oxazine-dione with full control of the newly formed stereocenter.

• MeSH
• acylace MeSH
• alkylace MeSH
• cyklizace MeSH
• kyselina trifluoroctová chemie   MeSH
• kyseliny karboxylové chemie   MeSH
• molekulární struktura MeSH
• morfoliny chemická syntéza   MeSH
• nitrobenzeny chemie   MeSH
• oxaziny chemie   MeSH
• polymery chemie   MeSH
• silany chemie   MeSH
• stereoizomerie MeSH
• techniky syntézy na pevné fázi metody   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH