Vinyl oxazolidinones

Oxazolidin-5-one, bis(trifluoromethyl)-reactions, 6, 213 Oxazolidinones polymers, 1, 281-282 reactions, 6, 213 Oxazolidinones, imino-rearrangement, 5, 775 Oxazolidinones, vinyl-polymers, 1, 281 Oxazolidin-2-ones circular dichroism, 6, 185 H NMR, 6, 181 IR spectroscopy, 6, 183 PE spectroscopy, 6, 183 reactions, 6, 213... 

Vinyl methyl benzimidazole Vinyl methyl dichlorosilane Vinyl methyl oxazolidinone Vinyl oxyethylurea Vinyl propionate Vinylpyridine Vinyl siloxane Vinylsuccinimide Vinyl stearate... 

Vinyl epoxides are highly useful synthetic intermediates. The epoxidation of dienes using Mn-salen type catalysts typically occurs at the civ-olefin. Epoxidations of dienes with sugar-derived dioxiranes have previously been reported to react at the trans-olefin of a diene. A new oxazolidinone-sugar dioxirane, 9, has been shown to epoxidize the civ-olefin of a diene <06AG(I)4475>. A variety of substitution on the diene is tolerated in the epoxidation, including aryl, alkyl and even an additional olefin. All of these substitutions provided moderate yields of the mono-epoxide with good enantioselectivity. 

The literature presents a large number of examples concerning the use of known oxazolidinones as chiral auxiliaries in many kinds of reactions. Rare is the use of A-amino derivatives of oxazolidinones, which were used to synthesise new A-acylhydrazones 207. Radical addition reactions occurred with high diastereoselectivity <00JA8329>. The use of glycolate oxazolidinones 210 proved to be efficient for the enantioselective preparation of a-alkoxy carboxylic acid derivatives . Photochemical reaction of vinyl... 

Allenamides are more stable and hence easier to handle in synthetic manipulations [152], When allenamide 187 was heated with 2equiv. of acrolein or methyl vinyl ketone (MVK), cycloadducts were isolated as single regioisomers. Allenamides containing either an oxazolidinone or imidazolidinone moiety also reacted with these a,/1-unsaturated carbonyl compounds under thermal conditions. 

Hegedus and co-workers8 reported the synthesis of (4S,5R)-4,5-diphenyl-3-vinyl-2-oxazolidinone (the enantiomer of the compound prepared here) via the chromium carbene complex in a fair yield. This is an interesting method, but the procedure is complicated (e.g., low temperature, argon atomsphere) and the chromium waste must be disposed of in an appropriate way. On the other hand, this procedure, consisting of transacetalization9 and pyrolysis,10 is simple and safe. Optically active 3-vinyl-2-oxazolidinone is also used for the synthesis of (1 R,2S)-2-fluorocyclopropylamine11a b that is the key intermediate for novel antibacterial quinolonecarboxylic acids. 

S,5R)-4,5-Diphenyl-3-vinyl-2-oxazolidinone 2-Oxazolidinone, 3-ethenyl-4,5-diphenyl-, (4S-cis)- (12) (128947-27-3)... 

C. (4R,5S)-4,5-Diphenyl-3-vinyl-2-oxazolidinone. A 500-mL filter flask is charged with (4R,5S)-3-(1-methoxyethyl)-4,5-diphenyl-2-oxazolidinone (8.9 g, 30 mmol) and solid ammonium chloride, NH4CI (0.32 g, 6.0 mmol). The flask is stoppered and heated behind a blast shield in a sand bath to 150°C - 170°C under reduced pressure via a water aspirator (ca. 11 mm) for 3 hr. The crude material is dissolved in CH2CI2 and run through silica gel with CH2CI2 (40 g of SiC>2, 250 mL of CH2CI2) to afford the product as a white solid (6.68 g, 84.2%) (Note 13). (A second treatment with silica is sometimes required to give completely clean product.)... 

The synthetic methods and chemical characterization data for the various polymeric materials to be discussed in this work have been reported elsewhere [6-8]. In some cases copolymerization of the unchlorinated oxazolidinone monomer with other common monomers such as acrylonitrile, vinyl chloride, styrene, and vinyl acetate, using potassium persulfate as an initiator, was performed. In other cases the unchlorinated oxazolidinone monomer was grafted onto polymers such as poly(acrylonitrile), poly(vinyl chloride), poly(styrene), poly(vinyl acetate), and poly(vinyl alcohol), again using potassium persulfate as an initiator. 

Results for the challenge of coated glass with S. aureus are shown in Table 1. The time of chlorination was a function of the hydrophilicity of the surface coating the poly(vinyl acetate oxazolidinone) polymers required the least amount of exposure to free chlorine. All of the surface coatings were effective against S. aureus in brief contact times. The grafted poly(acrylonitrile oxazolidinone) sample was not tested until 30 days after chlorination, but it still provided a 6-log inactivation of S. aureus in less than 10 min of contact. 

Poly(aorylonitrile-co-oxazolidinone), 2 = poly(vinyl aoetate-co-oxazolidinone), 3 = poly(acrylonitrile-g-oxazolidinone), 4 = poly(vinyl aoetate-g-oxazolidinone), 5 = poly(vinyl alcohol-g-oxazolidinone). Coatings were soaked in 3,000 mg/L free ohiorine. Time after ohiorination when biooidal effioaoy was measured. TABLE 2. Zones of inhibition of A/-Chioramine Poiymerio Biooidai Coatings on Fabric against Staphylococcus aureus. ... 

Poly(actylonitrile-co-oxazolidinone), 2 = poly(vinyl acetate-co-oxazolidinone), 4 = poly(vinyl acetate-g-oxazolidinone), 5 = poly(vinyl alcohol-g-oxazolidinone), 6 = poly(vinyl chloride-g-oxazolidinone). 

Poly(aorylonitrile-co-oxazolidinone, 2 = poly(vinyl acetate-co-oxazolidinone), 5 = poly(vinyl aloohol-g-oxazolidinone. 

Figure 4 Electron micrographs of unchlorinated poly(vinyl acetate-co-oxazolidinone) (top) and chlorinated poly(vinyl acetate-co-oxazolidinone) (bottom) coated medical catheters exposed for 72 h to a flowing aqueous suspension of Pseudomonas aeruginosa (10 CFU/mL). 

Diels-Alder reactions have featured heavily during the period of review. Ar-Vinyl-2-oxazolidinone has been reported as a dienophile for the first time, including the preparation of various tetrahydro-277,77/-pyrano[4,3-. ]pyrans <2002SL952>. The heterodiene cycloaddition reaction of 3-formylchromone with a series of ketene acetals formed from C2-symmetric l,2-diarylethane-l,2-diols is completely diastereoselective (Scheme 40) <1995J(P1)2293>. 

O) Assignment of the configuration at C-5 of the main isomer of 2-(2-methylpropyl)-5-vinyl-2-oxazolidinone (16) obtained in a cyclization reaction (see p 415), by conversion into the tert-bu-toxycarbonyl derivative of the natural amino acid statin 17127. 

The cyclization of carbamate derivatives of unsaturated amines has proven synthetically useful. Cyclizations of carbamates of allylamines containing a terminal vinyl group give oxazolidinone products (equation 60 and Table 17, entries 1 and 2).99,161 Bromocyclizations of systems with a di- or tri-sub-stituted alkene often give mixtures of oxazolidinones and tetrahydrooxazinones,163 while cyclization of an A -cinnamyl carbamate with phenylsulfenyl chloride gave only the oxazolidinone product.163b,163c The stereochemistry of the cyclization of primary carbamates of either allylic or homoallylic amines is low... 

Lipase-catalyzed enantioselective transesterification of 0-substituted-l,2-diols is another practical route for the synthesis of p-blockers. Lipase PS suspended in toluene catalyzes the transesterification of (63) with vinyl acetate to give the (5)-ester in 43% yield and >98% ee (78). The desired product, optically pure (R)-tritylglycidol, is then easily obtained by treating the ester with alcoholic alkali. Moreover, Pseudomonas lipase catalyzes the acylation of oxazolidinone (64) with acetic anhydride in very good yield and selectivity (74). PPL-catalyzed transesterification of a number of trans-norbomene derivatives proceeds in about 30% yield and 92% ee (79,80). 

Less satisfactory results have been frequently encountered in the related asymmetric cycloaddition of a vinyl epoxide to an isocyanate as in Scheme 8E.30 [160]. The modest enantioselectivities of this process are indicative of the competitive intramolecular nucleophilic addition with enantioface exchange. When the oxazolidinone was generated from an achiral substrate, somewhat higher enantioselectiviites were obtained presumably due to superposition of the enantioselection obtained in the ionization step. 

Neri et al89 reported the desymmetrization of A-Boc-serinol 98 by the selective monoacetylation using PPL (porcine pancreas lipase) and vinyl acetate as the acylating agent in organic solvent. The mono acetylated product (R)-99 was obtained after 2 hours with 99% ee and isolated in 69% chemical yield. Traces of the diacetylated product 100 were observed. The cyclization of (R)-99 in basic medium afforded the racemic oxazolidinone 101. The latter was subjected to enzymatic hydrolysis in phosphate buffer affording (R)-... 

Diels-Alder reactions of (Z)-A -substituted-4-methylene-5-propylidene-2-oxazoli-dinone dienes with methyl vinyl ketone, methyl propiolate, and captodative alkenes yield the highest regio- and stereo-selectivities in mixtures of H20 and MeOH or under BF3.Et20 catalysis.198 The asymmetric Diels-Alder reaction of cyclopentadiene and 3-acryloyl-2-oxazolidinone is catalysed by a new Cu(II) catalyst containing a chiral sterically congested roofed (2-diphenylphosphino)phenylthiazoline ligand (169).199... 

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