- 3,7-Dioxa-1-azabicyclo[3.3.0]octanes substituted at the C-5 position - From local to global stereochemistry
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Multiple approaches are described for the elucidation of the stereochemistry in solution (high-resolution NMR spectroscopy) and in the solid state (X-ray diffractometry) that are based on ab initio calculations (level RHF/6-31G*) of some representative 3,7-dioxa-1-azabicyclo[3.3.0]octanes. The results are presented in terms of conformational analysis, anomeric effects, chelating properties and aggregation phenomena. The significance of these findings with respect to diastereoselective synthesis is discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Darabantu, Mircea,Maiereanu, Carmen,Silaghi-Dumitrescu, Ioan,Toupet, Loic,Condamine, Eric,Ramondenc, Yvan,Berghian, Camelia,Ple, Gerard,Ple, Nelly
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- A convenient synthesis of 5-hydroxymethyl-1-AZA-3,7- dioxabicyclo[3.3.0]octane and its β-methoxyethoxy-methyl derivative
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5-(β-methoxyethoxymethyl)-1-aza-3,7-dioxabicyclo[3.3.0]-octane (1) was prepared in high yield by a reaction of tris-(hydroxymethyl)-aminomethane (TRIS) with β-methoxyethoxymethylchloride (MEMCl).
- Mattson,Norin
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- Antimicrobial oxazolidine/iodopropynyl-butyl carbamate composition containing less than 0.1 wt%free formaldehyde
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This invention relates to a broad spectrum antimicrobial composition, effective against gram negative and gram positive bacteria and fungi, which comprises a synergistic composition comprising iodopropynyl butyl carbamate and a bicyclic oxazolidine containing less than 0.1% of free formaldehyde.
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- Stereoelectronic control of oxazolidine ring-opening: Structural and chemical evidences
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Ring opening of oxazolidines derived from tris(hydroxymethyl)aminomethane, L-serine and L-threonine was investigated. It was shown that n(N)→σ*(C-O) electron delocalization (endo-anomeric effect) occurring in the five-membered ring plays a major role in the cleavage of the intracyclic C-O bond. The present work establishes that when the nitrogen lone pair is conjugated with a carbonyl group (n(N)→π(C=O) delocalization) as happens in N-acyloxazolidines, both hydrolysis and reductive ring-opening become much more difficult as a consequence of a concomitant decrease of oxygen basicity and of an increase of the intracyclic C-O bond strength.
- Sélambarom, Jimmy,Monge, Sophie,Carré, Francis,Roque, Jean Pierre,Pavia, André A
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p. 9559 - 9566
(2007/10/03)
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- Synthesis and stereochemistry of some 1,3-oxazolidine systems based on TRIS (α,α,α-trimethylolaminomethane) and related aminopolyols skeleton. Part 2: 1-Aza-3,7-dioxabicyclo[3.3,0]octanes
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The reaction of TRIS with equivalent amounts of two carbonyl compounds is shown to afford, diastereoselectively, the title compounds. The results are discussed as a synthetic strategy and the stereochemistry is supported by theoretical calculations and high resolution NMR data.
- Darabantu, Mircea,Plé, Gérard,Maiereanu, Carmen,Silaghi-Dumitrescu, Ion,Ramondenc, Yvan,Mager, Sorin
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p. 3799 - 3816
(2007/10/03)
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