2- Buten-l-one, 3-methyl-1-phenyl

Isopropyl alcohol, titanium (4+) salt, 65, 230 Isopropylideneacetophenone 2-Buten-l-one, 3-methyl-1-phenyl- ... 

Piloselloidon. 1 [ 5-Acetyl-2-hydroxy-3-(3-methyl-2-butenyl)phenyl]-3-methyl-2-buten-l-one, 1634... 

The results indicate that the product ratio is determined by the competition between the various reaction steps. When catalyzed by base, 2-butanone reacts with benzal-dehyde at the methyl group to give 1-phenyl-l-penten-3-one. Under acid-catalyzed conditions, the product is the result of condensation at the methylene group, namely, 3-methyl-4-phenyl-3-buten-2-one. Under the reaction conditions used, it is not possible to isolate the intermediate ketols, because the addition step is rate-limiting. These intermediates can be prepared by alternative methods, and they behave as shown in the following equations ... 

This test method has been found applicable to the measurement of impurities such as cumene, 3-methyl-2-cyclopentene-l-one, n-propylbenzene, fert-buytlbenzene, sec-butylbenzene, cw-2-phenyl-2-butene, acetophenone, 1-phenyl-1-butene, 2-phenyl-2-propanol, and fra s-2-phenyl-2-butene, which are common to the manufacturing process of AMS. The limit of detection for these impurities is 0.01 wt %. 

The disilanickela complex 21 was also found to be a good catalyst for the dehydrogenative double silylation of aldehydes. The nickel-catalyzed reactions of 1,2-bis(dimethylsilyl)carborane 11 with aldehydes such as isobutyraldehyde, trimethylacetaldehyde, hexanal, and benzaldehyde afforded 5,6-carboranylene-2-oxa-l,4-disilacyclohexane.32 34 36 The dehydrogenative 1,4-double silylation of methacrolein and tram-4-phenyl-3-buten-2-one in the presence of a catalytic amount ofNi(PEt3)4 also took place under similar conditions. In contrast, the reaction of 11 with a-methyl-tran.s-cinnamaldehyde and irans-cinnamaldehyde under... 

Catalytic asymmetric methylation of 6,7-dichloro-5-methoxy-2-phenyl-l-indanone with methyl chloride in 50% sodium hydroxide/toluene using M-(p-trifluoro-methylbenzyDcinchoninium bromide as chiral phase transfer catalyst produces (S)-(+)-6,7-dichloro-5-methoxy-2-methyl-2--phenyl-l-indanone in 94% ee and 95% yield. Under similar conditions, via an asymmetric modification of the Robinson annulation enqploying 1,3-dichloro-2-butene (Wichterle reagent) as a methyl vinyl ketone surrogate, 6,7 dichloro-5-methoxy 2-propyl-l-indanone is alkylated to (S)-(+)-6,7-dichloro-2-(3-chloro-2-butenyl)-2,3 dihydroxy-5-methoxy-2-propyl-l-inden-l-one in 92% ee and 99% yield. Kinetic and mechanistic studies provide evidence for an intermediate dimeric catalyst species and subsequent formation of a tight ion pair between catalyst and substrate. 

Similar levels of regiocontrol were observed in the condensation of A- N,N-diethylamino)-l,l,l-triflnoro-3-phenyl-3-buten-2-one and methyl-, phenyl-, and p-nitrophenyl hydrazines in acetonitrile (58-83 % yield). With methylhydrazine, the major isomer was the 3-triflnoromethyl-l-methyl-4-phenylpyrazole (ratio 2.5 1), whereas with phenylhydrazine, the 5-trifluromethylpyrazole analogue was the predominant component in a 11 1 mixture of isomers. This regioisomer was the only product observed when p-nitrophenylhydrazine was used [38]. 

C. (E)-3,3-Dimethyl-l-phenyl-1 -butene. In a 1-L, two-necked, round-bottomed flask fitted with a reflux condenser, rubber septum, and a magnetic stirring bar are placed 17.8 g (0.08 mol) of 2-methyl-2-(2-phenylethenyl)-1,3-dithiolane and 2.17 g (0.004 mol) of [1,3-bis(diphenylphosphino)propane]nickel(ll) chloride [NiCl2(dppp)] (Note 5). The flask is evacuated and flushed with nitrogen three times. To the above mixture is added 300 mL of anhydrous tetrahydrofuran (Note 6). The ether solution of methylmagnesium iodide prepared in Step B is introduced with a double-ended needle in one portion (Note 7). The mixture is heated under reflux for 24 hr, cooled to room temperature, and treated with 200 mL of saturated ammonium chloride solution. 

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