5.6- Dimethyl-2- 2- -ethenyl

Methan Bis-[trimethylsilyl]-brom-mercuri-(dimethyl-ethenyl-silyl)-E19d, 824 (Cl Li/+ HgBr2)... 

The nature of any solvent and the reaction temperature can also be of some importance. For the reaction between trimethyl phosphite and bromoacetone, carried out in diethyl ether at 30 °C, in MeOH or thf at 60 °C or in the absence of a solvent at 110-120 °C the yields of dimethyl (2-oxopropyl)phosphonate were 35, 28, 55 and 45%, whilst those of dimethyl ethenyl phosphate were 30,55,30 and 55%, respectively The proportion of oxoalkylphosphonate to enol phosphate for the reaction between triethyl phosphite and bromoacetone at 150 °C is 20 80, and this ratio is reversed if the reaction is carried out in boiling diethyl ether. Sometimes a change in both solvent and halogen produces a pronounced beneficial effect with regard to phosphonate formation thus the 80 20 advantage just noted for bromoacetone in diethyl ether is raised to 90 10 for chloroacetone at 150 °C, but for iodoacetone in boiling diethyl ether it is only 10 90 ... 

Methyl-6-aminobenzoselenazole when treated with 3-penten-2-one gave by a simple Doebner-Miller type reaction the 2,7,8-trimethylselenazoloquinoline 43 in 18.6% yield, that is the angular product and not the linearly annelated one was formed. Its structure was confirmed by the coupling constant in proton NMR (71JHC693). Selenazoloquinoline 43 can be converted via the 6-methylpyridium salt in the reaction with 4-dimethylaminobenzaldehyde to 2,6-dimethyl-7,9-bis(l-(4-dimethylaminophenyl)-2-ethenyl)selenazolo[5,4-/]quinolinium iodide 44 (Ar = 4-dimethylaminophenyl). This dye exhibited two absorption maxima between 500 and 600 nm (72MI2). 

Chemical Name 6-(dimethylamino)-2- [2-(2,5-dimethyl-1-phenyl-1 H-pyrrol-3-yl)ethenyl] -1-methylquinolium salt with pamoic acid (2 1)... 

CN [6/ -[3(Z),6a,7p(Z)]]-7-[[(2-amino-4-thiazolyl)(methoxyimino)acetyl]amino]-3-[2-(4-methyl-5-thiazolyl)ethenyl]-8-oxo-5-thia-1 -azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (2,2-dimethyl-1-oxopropoxy)methyl ester... 

A. Preparation of (2R,3S)- ana (2S,3S)-1,4-dioxa-2,3-dimethyl-2-(1-methyl-ethenyl)-8-carbcethoxy-8-azaspiro[4.5]decane. An oven-dried, 500-mL, three-necked, round-bottomed flask is fitted with a mechanical stirrer, 100-mL addition funnel, and rubber septum, and then is charged with 100 mL of dry tetrahydrofuran (Note 1) and... 

Figure 12.13 Pyrogram of a natural rubber latex paint. Peak assignments 1, isoprene 2, toluene 3, xylene 4, 4 ethenyl 1,4 dimethyl cyclohexene 5, limonene 6, dehydro p cymene...

However, most asymmetric 1,3-dipolar cycloaddition reactions of nitrile oxides with alkenes are carried out without Lewis acids as catalysts using either chiral alkenes or chiral auxiliary compounds (with achiral alkenes). Diverse chiral alkenes are in use, such as camphor-derived chiral N-acryloylhydrazide (195), C2-symmetric l,3-diacryloyl-2,2-dimethyl-4,5-diphenylimidazolidine, chiral 3-acryloyl-2,2-dimethyl-4-phenyloxazolidine (196, 197), sugar-based ethenyl ethers (198), acrylic esters (199, 200), C-bonded vinyl-substituted sugar (201), chirally modified vinylboronic ester derived from D-( + )-mannitol (202), (l/ )-menthyl vinyl ether (203), chiral derivatives of vinylacetic acid (204), ( )-l-ethoxy-3-fluoroalkyl-3-hydroxy-4-(4-methylphenylsulfinyl)but-1 -enes (205), enantiopure Y-oxygenated-a,P-unsaturated phenyl sulfones (206), chiral (a-oxyallyl)silanes (207), and (S )-but-3-ene-1,2-diol derivatives (208). As a chiral auxiliary, diisopropyl (i ,i )-tartrate (209, 210) has been very popular. 

Fig. 5 Structure of dyes forming aggregates in membranes (a) 2-[( )-2-[2-hydroxy-5-nitro-3-ll(Toxodocosyl)oxy]methyl]phenyl]ethenyl]-3,3-dimethyl- l-octadecyl-3//-indolium (PMC),...

A 1 1 mixture of (Z)- and ( )-tetramethylbicyclopropylidenes 24b,c was obtained by dihalocyclopropanation of dimethyl(dimethylethenylidene)cyclopro-pane 27 [45,46] followed by reduction of the adducts with sodium in methanol (Scheme 6). Addition of monochlorocarbene onto 2-(trimethylsilyl)-l-ethenyl-idenecyclopropane (29) proceeds with low diastereo- and regioselectivity to give a mixture of bicyclopropylidene and methylenespiropentane derivatives 30, 31 in poor yield [47]. Upon treatment of l,l-dibromo-2-methylpropene (36) with butyllithium at -110°C the unique diisopropylidenetetramethylbicyclo-propylidene 37 was formed by addition of isobutylidene to in situ generated tetramethylbutatriene (32), albeit in very low yield [48] (Scheme 7). 

Beccalli et al. reported a synthesis of carbazomycin B (261) by a Diels-Alder cycloaddition using the 3-vinylindole 831 as diene, analogous to Pindur s synthesis of 4-deoxycarbazomycin B (619). The required 3-vinylindole, (Z)-ethyl 3-[(l-ethoxy-carbonyloxy-2-methoxy)ethenyl]-2-(ethoxy-carbonyloxy)indole-l-carboxylate (831), was synthesized starting from indol-2(3H)one (830) (620). The Diels-Alder reaction of the diene 831 with dimethyl acetylene dicarboxylate (DMAD) (535) gave the tetrasubstituted carbazole 832. Compound 832 was transformed to the acid 833 by alkaline hydrolysis. Finally, reduction of 833 with Red-Al afforded carbazomycin B (261) (621) (Scheme 5.99). 

Aus den Synthesekomponenten C —N-C—N + C ist nur die Herstellung von 5-(2,6-Dimethyl-anilino)- -(2,6-dimethyl-phenyl)-4-(1-ethoxycarbonyl-ethenyl)-2-(4-nitro-phenyl)-imidazol in 89% Ausbeute aus 2,6-Dimethyl-phenylisocyanid mit 4-Nitro-benzoesaure-(2,6-dimethyl-phe-nylimid)-(2-ethoxycarbonyl-l-propenylidenamid) beschrieben306. 

Analog gelingt die Synthese von 1-Ethenyl-l-nitro-cyclohexan (67%), 3,6-Dimethyl-3-nitro- (70%), 3-Me-thyl-3-nitro-6-oxo- (74%) und 6-Benzyl-3-methyl-3-nilro-hexan (60%)5. 

Die Anwendung ahnlicher Bedingnngen auf 2,2-Dimethyl-oxetan und 2-Ethenyl-oxetan fiihrt zu 2-Amino-4-hydroxy-2-methyl-kutan bzw. 3-Amino-5-hydroxy-l-penten5 ... 

C2H6C14N2P2, Phosphorodichloridous hydraz-ide, 2-(dichlorophosphino)-1,2-dimethyl-, [37170-64-2], 32 133-34 C2H8B3N3, Borazine, 2-ethenyl-, [110272-04-3], 32 237-39... 

Hydroxy-3-methoxy-[(2S,3aR,3bS, 6aR,9aR,9bR, 10R,11aR)-3a,3b,6,6a,9a,10,11,11a-octahydro-6a-hydroxy-8,10-dimethyl-11a-(1-methyl-ethenyl)-7-oxo-2-(phenyl-methyl)-7H-2,9p-epoxy-azuleno[5,4-e]-1,3-benzo-dioxol-5-yl]benzeneacetic acid, C37H40O91 Mr 628.71. 

Pentene I-(1.2-Difluoro-ethenyl-oxy)-4.4-dimethyl- E10b2. 204f. (F2C=CF —SiRj +... 

Silane Dimethyl-phenyl-(trifluoro-ethenyl)- ElOb, 420 (Educt)... 

Octenoic Acid 2-Chloi 0-3.7 dimethyl-3-ethenyl-2-fluoro-ElOhj, 199f. (F - OH)... 

CYCLOPENTANONE SYNTHESIS, 66, 87, 92, 93 Cyclopentanone, 2-carbomethoxy-3-vinyl, 66, 56 Cyclopentanone, 2-ethenyl-2-methyl (88729-76-4), 66, 94 Cyclopentene (142-29-0), 67, 157 4-Cyclopentene-1,3-diol, monoacetate, cis-, 67, 114 2-Cyclopenten-1-one, 4,4-dimethyl-, 67, 121,205 2-CYCLOPENTEN-1 -ONE, 3-METHYL-2-PENTYL-, 65, 26 CYCLOPROPANATION, 67, 176... 

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