[reaction: see text] The reaction between alpha-glycosyl bromides and potassium p-methylselenobenzoate yields beta-p-methylbenzoyl selenoglycosides. The acyl selenoglycosides were activated by the action of a secondary amine and Cs2CO3 to produce an anomeric selenolate anion, which reacted in situ with various electrophiles to yield novel selenoglycosides while retaining the anomeric stereochemistry.

Selenapenams, selenacephems, and selenazepines were synthesized using a 2-(trimethylsilyl)ethyl (TSE) protection approach in an extremely simple way. TSE protection for selenium is used for the first time in the synthesis of selenium-containing beta-lactam. Novel intramolecular cycloaddition reaction of selenium with alkynes and allenes is used in the present synthesis.

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Carbohydrates U 0500A Facile Method for β-Selenoglycoside Synthesis Using β-p-Methylbenzoyl Selenoglycoside as the Selenating Unit. -Acylseleno glycosides (I) and (VI) are activated by the action of a secondary amine and Cs2CO3 to produce an anomeric selenolate anion, which reacts in situ with various electrophiles. Novel selenoglycosides including selenooligosaccharides and selenoglycosylamine are obtained with retention of anomeric stereochemistry. -(KAWAI, Y.; ANDO, H.; OZEKI, H.; KOKETSU, M.; ISHIHARA*, H.; Org. Lett. 7 (2005) 21, 4653-4656; Dep. Chem., Fac. Eng., Gifu Univ., Yanagido, Gifu 501-11, Japan; Eng.) -Klein 09-202

Organo-selenium compounds S 0130Synthesis of Novel Selenapenams, Selenacephems, and Selenazepines Using a 2-(Trimethylsilyl)ethyl Protection Approach. -The novel selenating reagent (III) is used to incorporate the Tse-protected seleno moiety on the β-lactam skeleton (IV) with complete retention of configuration. The precursor (V) thus obtained undergoes a series of N-alkylation and deprotection/ring closure reactions to give title compounds, which are expected to exhibit interesting biological properties. -(GARUD, D. R.; ANDO, H.; KAWAI, Y.; ISHIHARA*, H.; KOKETSU*, M.; Org. Lett. 9 (2007) 22, 4455-4458; Dep. Chem., Fac. Eng., Gifu Univ., Yanagido, Gifu 501-11, Japan; Eng.) -Kieslich 13-175