Oxirane 2-methyl-3-phenyl

Oxirane, 2-methyl-3-phenyl-, (2R,3R)- and 7-Oxabicyclo[4.1.0]heptane,l-phenyl-... 

Analog ergibt 2-Methyl-2-phenyl-oxiran 2-Phenyl-propanol (100% d. Th.) und tram-3-Methyl-2-phenyl-oxiran l-Phenyl-propanol-(2) (97% d.Th.). 

By the extension of the above-mentioned stereoselective asymmetric addition of alkylithiums to other organolithium reagents such as lithium salts of methyl phenyl sulfide, 2-methylthiazoline, trialkylsilylacetylene, N-nitroso-dimethylamine, and acetonitrile, chiral oxiranes (95) U1), thiiranes (96) nl), acetylenic alcohols (98) 112), and amino alcohols (97) U1) were readily obtained. 

Oxiran trcms-3-( Diazo-acetyl)-2-phenyl- E14b, 1194 (Oxiran-Bild.) Propansaure 2-Hydroximino-3-(4-methyl-phenyl)-3-oxo- -nitril X/4, 159... 

Dioxolan 4-Chlormethyl-2-(4-methyl-phenyl)- E14a/1, 292 (Oxiran -l- Ar —CHO)... 

Oxiran 2-Methyl-3-(4-methyl phenyl)-2-trimethyl-silyl- E19d, 881 (H - Li/ + R-CHO) Propen 2-Methyl-l-phenyl-1-trimethylsilyloxy- E1S/1, 441 (Keton + R3Si —O —S02 —R) Silan Dimethyl-pentanoyl-phenyl-E19d, 570 (Acylierung) Spiro[4.4]nona-2,6-dien 6-Methyl-l -oxo-2(bzw. 3)-trimethylsiiyl-E19c, 221 (3-En-CO-Cl +... 

Biodegradable polyesters were synthesized via ring-opening copolymerizations of various oxiranes (glycidyl phenyl ether, benzyl glycidate, glycidyl methyl ether, styrene oxide) and various dicarboxylic anhydrides (succinic anhydride, phthalic... 

Scheme 4.26 Basic enzymatic polymerization of oxiranes (Glycidyl phenyl ether GPE benzyl glycidate BG glycidyl methyl ether GME styrene oxide SO) and dicarboxylic anhydrides (succinic anhydride SA maleic anhydride MA phthalic anhydride PA).

Entsprechend diesen Regeln erhalt man aus (4-Methyl-phenyl)-oxiran in quantitativer Ausbe ute 2-( 4-Methyl-phenyl) - athano l1 ... 

Durst and coworkers were the first to report the condensation of chiral a-sulphinyl carbanions with carbonyl compounds477. They found that metallation of ( + )-(S)-benzyl methyl sulphoxide 397 followed by quenching with acetone gives a mixture of dia-stereoisomeric /i-hydroxy sulphoxides 398 in a 15 1 ratio (equation 233). The synthesis of optically active oxiranes was based on this reaction (equation 234). In this context, it is interesting to point out that condensation of benzyl phenyl sulphoxide with benzaldehyde gave a mixture of four / -sulphinyl alcohols (40% overall yield), the ratio of which after immediate work-up was 41 19 8 32478. 

Mit Natriumboranat gelingt es z. B. 3-Brommethyl-2-phenyl-oxiran (HMPT/700, 12 Stdn.) zum 3-Methyl-2-phenyl-oxiran (63% d.Th.) zu reduzieren1. 

Reaction of the carbanion of chloromethyl phenyl sulphoxide 409 with carbonyl compounds yields the corresponding 0-hydroxy adducts 410 in 68-79% yield. Each of these compounds appears to be a single isomer (equation 242). Treatment of adducts 410 with dilute potassium hydroxide in methanol at room temperature gives the epoxy sulphoxides 411 (equation 243). The ease of this intramolecular displacement of chloride ion contrasts with a great difficulty in displacing chloride ion from chloromethyl phenyl sulphoxide by external nucleophiles . When chloromethyl methyl sulphoxide 412 is reacted with unsymmetrical ketones in the presence of potassium tcrt-butoxide in tert-butanol oxiranes are directly formed as a mixture of diastereoisomers (equation 244). a-Sulphinyl epoxides 413 rearrange to a-sulphinyl aldehydes 414 or ketones, which can be transformed by elimination of sulphenic acid into a, 8-unsaturated aldehydes or ketones (equation 245). The lithium salts (410a) of a-chloro-/ -hydroxyalkyl... 

Carbon-13 shift values of parent heterocycloalkanes [408] collected in Table 4.61 are essentally determined by the heteroatom electronegativity, in analogy to the behavior of open-chain ethers, acetals, thioethers, thioacetals, secondary and tertiary amines. Similarly to cyclopropanes, three-membered heterocycloalkanes (oxirane, thiirane, and azirane derivatives) display outstandingly small carbon-13 shift values due to their particular bonding state. Empirical increment systems based on eq. (4.1) permit shift predictions of alkyl- and phenyl-substituted oxiranes [409] and of methyl-substituted tetrahydropyrans, tetrahydrothiapyrans, piperidines, 1,3-dithianes, and 1,3-oxathianes [408], respectively. Methyl increments of these heterocycloalkanes are closely related to those derived for cyclohexane (Table 4.7) due to common structural features of six-membered rings. 

Methyl 3,3-Di luoro-2-phenyl- ElOa, 379 (Ar-oxirane-COOR + SF4)... 

Propanoate Methyl 3-Fluoro-2-hydroxy-3-phenyl- ElOb, 150 (Oxirane + HF R2NH)... 

Butanoatc Methyl 3-F uoro-2-hydroxy-3-phenyl- ElOb, 150 (Oxirane + HF/NRjH) Ethanoate Ethyl Fluoro-(4-methoxy-phenyl)- F.lOb, 107 (OH - I ) Propanoate Ethyl 2-Fluoro-3-hydroxy-3-phcnyl- ElOb,. 454 (R -CHO + F —CH, — COOR) E10b2, 52 (Educt)... 

Dccyloxy-phenyl) 4-j[2-(3,3-Dimethyl-butyl)-oxiran-2-yl]-fliioro-methyl - ElOb, 89 (OH - F)... 

Fig. 2. Mechanism of BF-,-catalysed rearrangement of isomeric 2-methyl-3-phenyl-oxiranes to l-phenyl-2-propanone (3).

The (R) allene 121 was obtained with high anti stereoselectivity in the reaction of (i )-(—)-l-trifluoroacetoxy-l-phenyl-2-propyne (120) with PhZnCl. 2-Alkynyloxiranes react smoothly with alkynyl, alkenyl and arylzinc reagents. Reaction of 2-methyl-2-(l-propynyl)oxirane (122) with vinylzinc chloride (123) yields 2,4-dimethyl-2,3,5-hexatrien-l-ol (124) [31],... 

The reaction of the sodium salt of (R)-Ar-(p-tolylsulfonyl)-5-methyl-5-phenyl-sulfoximine 2a (84% ee) with acetophenone at room temperature gave (-)-(S)-2-methyl-2-phenyloxirane.18The (S)-oxirane product must arise from the collapse of... 

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