4-Methyl-2-phenyl-3-penten

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

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. 

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. 

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°. 

H and 13C KIEs were determined for the ene reaction of 4-phenyl-l,2,4-triazoline-2,5-dione (PTAD) with 2-methyl-2-butene 44 or 2-methyl-l-pentene 45 (Scheme 7).91 Authors assumed that although in the reaction of 2-methyl-l-pentene two products are formed, reactions should proceed via very similar transition states in the first mechanistic step. 

A completely different course of reaction was established when one or both benzylic protons in the benzyl alcohol molecule were replaced with phenyl or methyl substituents diphenyl methanol gives bis(diphenylmethyl) ether, while 2-phenyl-2-propanol was transformed to 2,4-diphenyl-4-methyl-l-pentene)106 (Scheme 40). 

The phenyl tellurium tribromide can be prepared in situ from diphenyl ditellurium and bromine. Olefins thus far investigated include isobutene, (E)- and (Z) -butene, 1 -hexene, 2-methyl-l-pentene, 1-octene, (E)- and (Z)-4-octene, 1-decene, phenylethene, 1-phenyl-I-methylethene, cyclopentene, cyclohexene, cycloheptene, and cyclooctene. Most of the reactions were carried out with phenyl tellurium tribromide in methanol. 

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... 

The butyllithium-generated anion of an allylic sulfone was reported to add to conjugate enones, but different regioselectivity was observed for 2-cyclohexenone (1,4-y) and 3-penten-2-one (1,4-a), as shown in equation (31). Clean 1,4-a additions to both acyclic and cyclic enones can be realized when the lithio carbanions are allowed to react in the presence of HMPA (2 mol equiv.) at -78 C. Under these conditions, allyl phenyl sulfone reacts with 2-cyclohexenone. 2-methyl-2-cyclopentenone and 3-methyl-2-cyclohexenone, giving the corresponding 1,4-a adducts as a 75 25 mixture of two dia-stereoisomers. In the reaction of allylic phenyl sulfone with an acyclic enone, 4-methyl-3-penten-2-one,... 

Recently reported synthetic studies en route to the epothilones documents a series of fascinating observations by Danishefsky of a novel aldol addition reaction (Eq. (8.10)). The epothilone strategy necessitated an unusual aldol addition reaction of 38 and (5 )-2-methyl-4-pentenal. The addition reaction gave a stereochemical outcome unexpected on the basis of the accepted models for acyclic stereocontrol in carbonyl addition reactions. Thus, the addition affords adduct 39 and 40 as a 5.5 1 diastereomeric mixture with an unexpected preference for the anti-Cram adduct. By contrast, addition to (S)-phenyl acetaldehyde affords the Cram adduct as an 11 1 mixture of diastereomers. In a series of studies, Danishefsky has noted that the positioning of unsaturation in the substrate in relation to the aldehyde C=0 appears to be critical. 

Franke, A., Mattern, G.. and Traber, W., Synthetical juvenile hormone. Part 4. pfiira-Substituted 2-methyl-5-phenyl-penten(l)-carboxylic acid derivatives, Helv. Chim. Acta, 58, 293, 1975. 

Treatment of 2-methyl-l-penten-3-ol with phenyl chlorothionoformate leads to a 96.5 3.5 EjZ mixture of the rearranged product 1 in 67% yield308. The reaction of 2-methyl-l-penten-3-ol with phenyl dithiochloroformate gives 5-2-methyl-2-pentenyl 5-phenyl dithiocarbonate (2) in 30% yield and >99% 308. 

A solution of 1.2 g (1.2 mmol) of 2-methyl-l-penten-3-ol in 10mL of pyridine is cooled to — 20 °C, and 2.2 g (1.28 mmol) of phenyl chlorothionoformate are added with stirring. After 1 h the product is poured into H20, and the organic material is extracted with Et20. The ethereal layers are washed with 2 N NaOH, H20, 3 N HC1, and H20 again. The combined ethereal layers are dried over anhyd Na2S04, and the solvent is evaporated. The residue is distilled to obtain the thiolcarbonate as a pale yellow oil vield 1.77 g (67%) bp 110°C/1 Torr. 

A less general method involves transfer of a chiral group from the cuprate to the enone. The chiral Gilman reagent [R 2CuLi, R = (R)-2-(l-dimethylamino)phenyl] reacted with (4 )-methyl-3-penten-2-one (473) to give 474 in 30% yield and 80% ee. 33 Reaction of the mixed cuprate [ThR CuLi where Th = 2-thienyl and R = (R)-2-(l-dimethylamino)phenyl] gave 474 in 70% yield (82% ee). 3... 

The concerted nature of the reaction is indicated by the fact that a Markovnikoff-type directing effect is essentially absent. Secondary and tertiary products are formed in nearly equal amounts from unsymmetri-cally substituted olefins (9, 13, 14, 15, 17, 27, 34). In addition, substituents on the phenyl group of trimethylstyrene exert no effect on the product distributions (12). Furthermore, values for 2-methyl-2-pentene show only a very small solvent effect (12). All these facts suggest that little polarity is developed at the transition state and are consistent with a concerted reaction. 

Poly (4-methyl-1-pentene) Poly-4-methylpentene-1. See Polymethylpentene Polymethylphenyl siloxane. See Phenyl methicone... 

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] ... 

To understand the reasons for different predictions of different methods, Li et al. [83] measured the adhesion between a variety of polymers with well-controlled backbone chemistry These polymers include poly (4-methyl 1-pentene) [TPX], poly(vinyl cyclohexane) [PVCH], polystyrene [PS], poly(methyl methacrylate) [PMMA], and poly(2-vinyl pyridine) [PVP], poly(4-tert-butyl styrene) [PtBS], poly(acrylonitrile) [PAN], poly(p-phenyl styrene) [PPPS], poly(vinyl benzyl chloride) [PVCB]. It may be noted that, among the polymers listed above, TPX and PVCH are purely dispersive in nature. PS is predominantly dispersive with some dipole-induced dipole interactions. 

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