4- PENTENAL, 2-METHYL-2-PHENYL

METHYL-2-PHENYL-4-PENTENAL 4-PENTENAL, 2-METHYL-2-PHENYL- ... 

GEHIKAL ACYLATION-ALKYLATION AT A CARBONYL CENTER USING DIETHYL N-BEN ZYLIDENEAMINOMETHYLPHOSPHONATE PREPARATION OF 2-METHYL-2-PHENYL-4-PENTENAL (4-Pentenal, 2-methyl-2-phenyl-)... 

Davidsen, S.K., Phillips, G.W., and Martin, S.F., Geminal acylation-alkylation at a carbonyl center using diethyl IV-benzylideneaminomethylphosphonate. Preparation of 2-methyl-2-phenyl-4-pentenal (4-Pentenal, 2-methyl-2-phenyl-), Org. Synth., 65, 119, 1987 Org. Synth. Coll. Vol. VIII, 451, 1993. 

Analog reagiert Brom-ethen mit 3,3-Dimethoxy-propen und Piperidin bei 100° (20 h) in Gegenwart von Palladium-acetat und Tris-[2-methyl-phenyl]-phosphan zu 5,5-Dimethoxy-1 -piperidim-2-penten (57%)2. 

JV- Methyl-iV-(2 -methyl-phenyl)amino]-2-pentene (194) (Z)-3-[iV-Methyl-iV-(2 -methylphenyl)-amino]-2-pentene (195) ( )-4-(iV-Phenylamino)-3-heptene... 

Styrene 4-Methyl-1 -pentene 1 -Phenyl-7-methyl-3-octanone 62 96... 

A solution of 16.0 g a-allylbutyrophenone in 180 mL rm-butyl alcohol was irradiated under nitrogen in an immersion well with a Pyrex-filtered 450-W Hanovia mercury arc until < 10% of the starting ketone remained. GC analysis showed six products, but none of products was identified as 3-methyl-l-benzoylcyclopentane. After stripping of the solvent, the residue was chromatographed on neutral alumina with cyclohexane/CHCl3 (1 1) as the eluent to afford five components, of which the first three were further purified by GC through a column packed with 15% QF-1 and 3% Carbowax. These compounds were 1 -phenyl-3-penten-1 -one, 4-phenyl-3-ethyl-4-pentenal, 1 -phenyl-2-aUylcyclobutanol, 2-phenylbicyclo[2.2. l]heptanol-2, and 3-phenyl-4-ethyl-3-cyclopentenol. 

Polymerizations of many internal olefins, like 2-butene, 2-pentene, 3-heptene, 4-methyl-2-pentene, 4-phenyl-2-butene and others, with Ziegler-Natta catalysts are accompanied by monomer rearrangements. The isomerizations take place before insertions into the chains [311-318] ... 

Methyl-3-penten-2-one. See Mesityl oxide Methyl-4-(phenylthio)phenyl sulfoxide,... 

Intramolecular secondary aminostyrenes 95-97 were also studied100. iV-2,2-Trimethyl-3-phenyl-3-buten-l-amine 95 was irradiated to obtain the elimination product 98 (equation 29). Irradiation of Af-methyl-4-phenyM-penten-l-amine 96 results in a single product 99 in 80% yield by GC analysis (equation 30). Similarily, irradiation of iV-methyl-5-phenyl-5-hexen-l -amine 97 results in the formation of a single product 100 in 70% yield (equation 31). The photochemistry of the (aminopropyl) indene 101 is also similar (equation 32). 

Capillary gas chromatography is conducted with a cross-linked phenyl methyl silicone stationary phase (5%, 25 m x 0.2 mm x 0.5 pm film thickness, injector temp. 225°C, detector temp. 250°C, column temp. 40-200°C, 15°C/min after 1 min initial time). (Z)-2-Bromo-5-(trimethylsilyl)-2-penten-4-ynoic acid ethyl ester is observed to have a retention time of 14.0 min. GC data for bis(trimethylsilyl)butadiyne is as follows retention time 10.0 min, response factor (GC area produced relative to an equimolar quantity of (Z)-2-bromo-5-(trimethylsilyl)-2-penten-4-ynoic acid ethyl ester) 1.29. For (E)-2-[(trimethylsilyl)ethynyl]-5-(trimethylsilyl)-2-penten-4-ynoic acid ethyl ester the retention time is 17.0 min, the response factor 1.19. 

Cathodic reduction of 1,3-diphenyl-propenone leads to l-hydroxy-2-benzoyl-3,4-diphenyl cyclopentanes with exclusive cis configuration of the two phenyl groups. With l-phenyl-l-pentene-3-one the cyclodimer 2-methyl-3,5-diphenyl-4-(l-propionyl)-cyclohexanone is formed with a 100% yield in an intramolecular Michael addition via an electrogenerated base. The substituents are all in the most stable equatorial position [277]. 

Steele, W.V., Chirico, R.D., Cowell, A.B., Knipmeyer, S.E., and Nguyen, A. Thermodynamic properties and ideal-gas enthalpies of formation for 2-aminoisobutyric acid (2-methylalanine), acetic acid, ( -5-ethylidene-2-norbornene, mesityl oxide (4-methyl-3-penten-2-one), 4-methylpent-l-ene, 2,2 -bis(phenylthio)propane, and glycidyl phenyl ether (1,2-epoxy-3-phenox3q>ropane), / Chem. Eng. Data, 42(6) 1053-1066, 1997. 

Mit dem gleichen Reagenz erhalt man z. B. aus N-Propyl-benzaldimin erythro-4-Methyl-5-phenyl-5-propylamino-l-penten (75%) und aus N-Benzyl-benzaldimin 5-Benzylamino-4-methyl-5-phenyl-1-penten (90% erythro threo = 8 92)2 analog erhalt man aus 2-Phenyl-propanal-isopropylimin mit 9-Allyl-9-bora-bicyclo[3.3.1]nonan erythro-4-Isopropylamino-5-phenyl-l-hexen ( 90%)1. 

Beispiele fur die reduktive Spaltung sind die zu 4-Amino-4-methyl-3-phenyl-2-penten (75%), 4-Amino-3-phenyl-2-penten (79%) bzw. zu l-Amino-2-ethyliden-cyclohexan fuhrenden Re-duktionen von 2-Ethenyl-aziridinen mit Diboran1. 

The hydroformylation of several olefins in the presence of Co2(CO)8 under high carbon monoxide pressure is reported. (S)-5-Methylheptanal (75%) and (S)-3-ethylhexanal (4.8%) were products from (- -)(S)-4-methyl-2-hexene with optical yields of 94 and 72%, respectively. The main products from ( -)(8)-2,2,5-trimethyl-3-heptene were (S)-3-ethyl-6,6-di-methylheptanal (56.6%) and (R)-4,7,7-trimethyloctanal (41.2%) obtained with optical yields of 74 and 62%, respectively. (R)(S)-3-Ethyl-6,6-dimethylheptanal (3.5% ) and (R)(S)-4,7,7-trimethyloctanal (93.5%) were formed from (R)(S)-3,6,6-trimethyl-l-heptene. (+/S)-l-Phenyl-3-methyl-1-pentene, under oxo conditions, was almost completely hydrogenated to (- -)(S)-l-phenyl-3-methylpentane with 100% optical yield. 3-(Methyl-d3)-l-butene-4-d3 gave 4-(methyl-d3)pentarwl-5-d3 (92%), 2-methyl-3-(methyl-d3)-butanal-4-d3 (3.7%), 3-(methyl-d3)pentanal-2-d2,3-d1 (4.3%) with practically 100% retention of deuterium. The reaction mechanism is discussed on the basis of these results. 

S)-l-Phenyl-3-methyl-l-pentene, initially synthesized to extend the data obtained with (+)(S)-2,2,5-trimethyl-3-heptene, under usual oxo conditions is almost completely hydrogenated with an optical yield of practically 100% while the hydroformylation products are barely detectable. 

S)-1-Phenyl-3-methyl-1-pentene. Freshly distilled benzalde-hyde (53 grams, 0.5 mole) was added slowly (2 hrs) at 0°C to a solution in ethyl ether (400 ml) of a Grignard reagent prepared from ( + )(S)-1-bromo-2-methylbutane [75.5 grams, 0.5 mole) [ ]D25 + 3.968, op 97.2% (20)] and Mg (12 grams). 

The alcohol obtained after usual work up was heated at 170 °C in the presence of CuS04 (40 grams) for 5 hrs. The crude olefin was recovered by distillation and then purified by rectification under reduced pressure. ( + ) (S)-l-Phenyl-3-methyl-l-pentene (trans) (40 grams) was thus obtained (bp 113°C at 18 mm Hg, nD25 1.5242, D25 +44.95°) (21). 

A portion of the olefin (3.5 grams) dissolved in pentane (10 ml) was treated with ozone at —178°C for 8 hrs. The product was treated with excess LiAlH4 in ether at 0°C and refluxed. After usual work up, benzyl alcohol (1.7 grams) and (—)(S)-2-methyl-l-butanol [1.1 grams [< ]D25 —5.50, op 94.5% (16, 17)] were recovered. An optical purity of 94.5% is attributed to ( + )(S)-l-phenyl-3-methyl-l-pentene having D25 +44.95°. 

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