3-Methyl-3-butene-2-one

MEK is a colorless, stable, flammable Hquid possessing the characteristic acetone-type odor of low molecular weight aUphatic ketones. MEK undergoes typical reactions of carbonyl groups with activated hydrogen atoms on adjacent carbon atoms, and condenses with a variety of reagents. Condensation of MEK with formaldehyde produces methylisopropenyl ketone (3-methyl-3-buten-2-one) ... 

Methyl Isopropenyl Ketone. Methyl isopropenyl ketone [814-78-8] (3-methyl-3-buten-2-one) is a colorless, lachrymatory Hquid, which like methyl vinyl ketone readily polymerizes on exposure to heat and light. Methyl isopropenyl ketone is produced by the condensation of methyl ethyl ketone and formaldehyde over an acid cation-exchange resin at 130°C and 1.5 MPa (218 psi) (274). Other methods are possible (275—280). Methyl isopropenyl ketone can be used as a comonomer which promotes photochemical degradation in polymeric materials. It is commercially available in North America (281). 

An enantioselective Michael addition reaction was also accomplished in an inclusion complex with a chiral host compound. Treatment of a 1 1 complex of 10c and 66b with 2-mercaptopyridine (137) in the solid state gave (+)-138 of 80% ee in 51% yield. By a similar method, 3-methyl-3-buten-2-one (139) gave (+)-140 of 49% ee in 76% yield [30]. 

The reaction proceeds primarily by addition to a double bond to form a chlorine-containing alkyl radical, which then adds 02 to ultimately generate characteristic chlorine-containing oxygenated products. For example, l-chloro-3-methyl-3-buten-2-one is formed in the absence of NO from the addition of chlorine atoms to the 4-position of isoprene, followed by secondary reactions of the alkyl radical with 02 etc. This product might therefore be expected to be a reaction product in the low-NOj. environment of the marine boundary layer (Nordmeyer et al., 1997). 

Methylenomycins.1 The cyclopentannelation reaction (12,310) has been modified to provide a general synthesis of methylenomycins. Thus, the adduct (2) of a-lithio-a-(methoxymethyl)allene (1) with 3-methyl-3-butene-2-one cyclizes to methylenomycin B (3) in the presence of trifluoroacetic anhydride and 2,6-lutidine. 

Similar treatment of the 1 1 inclusion complex of 3-methyl-3-buten-2-one (13) and 5c with 11 gave the addition product 14 of 49 % ee in 76 % yield [8],... 

Taking into account [81,82] that photodegradation of poly(4,4-dimethyl-l-penten-3-one) [poly(BVK)] and poly(3-methyl-3-buten-2-one) [poly(MIK)] proceeds predominantly through a Norrish type I mechanism via the triplet state (Scheme 15), the above homopolymers have been studied as initiators in the photoinduced polymerization of vinyl monomers such as MMA, St, AN and VAc [83]. 

Michael addition of 65 to 3-methyl-3-buten-2-one (68) in its inclusion ciystal with 2c also occuired enantioselectively. When the complex of 68 with 2c was treated with 65a-f in the presence of a catalytic amount of 66 under the same conditions as for the reaction shown in Table 15-17, products 69a-f were obtained in the optical purities shown in Table 15-18. The optical purities of 69a and 69d were relatively higher, but those of 69b and 69c were lower, whilst, in the case of 69e and 69f, enantiocontrol was not manifested [32]. It has been reported that some of the solid state organic reactions are accelerated by an irradiation of ultrasound [33]. 

Enol borinates are also intermediates in the reaction of organoboranes with z,/5-unsaturated ketones and aldehydes. Thus the reaction of triethylborane and 3-methyl-3-butene-2-one (5) followed by addition of (2, in DMSO) affords the Mannich base (6) in 87% yield. 

The acid base pairs selectivity is the sum of selectivity in 3-hydroxy 3-methyl butan-2-one, in 3-methyl 3-buten 2-one and methylisopropylketone which are formed supposedly to be on acid-base pairs. 

METHYL-3-BUTEN-2-ONE (German) (814-78-8) see methyl isopropenyl ketone. 1-METHYLBUTYL ACETATE (626-38-0) C7H14O, CH3COOCH(CH3)C3Ht Forms explosive mixture with air [explosion limits in air (vol %) 1.0 to 7.5 flash point 89°F/32°C autoignition temp 716°F/380°C Fire Rating 3]. Violent exothermic reaction... 

Methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one. AI3-36074 3-Buten-2-one, 3-methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)- Cetone a a-Cetone EINECS 204-846-3 FEMA No. 2714 a-ionone, isomethyl- Isomethyl-a-ionone Isomethylionone, a- Methyl-a-isoionone 3-Methyl-4-(2,6,6-trimethyl-2-cyclohexen-1-yl)-3-buten-2-one NSC 66432 4-(2,6,6-T rimethyl-2-cyclohexen-1 -yl)-3-methyl-3-buten-2-one. 

Thus an almost quantitative yield of ethyl l-(hydroxymethyl)-2-oxocyclo-hexanecarboxylate is obtained from ethyl 2-oxocyclohexanecarboxylate and aqueous formaldehyde in the presence of calcium oxide 687 and 2-butanone and formaldehyde in sodium hydroxide solution give a 70% yield of 4-hydroxy-3-methyl-2-butanone, whence 3-methyl-3-buten-2-one is formed in 74% yield by removal of water.688 Hydroxymethylation of acetone689 and of co-nitrotoluene (phenylnitromethane)690 have also been reported. 

Naito et al. have examined the photopolymerization of methyl methacrylate initiated by poly(3-methyl-3-buten-2-one). Again a-cleavage was found to be the dominant initiating step. The photoinitiated polymerization of methyl methacrylate by benzophenone derivatives has been found to depend upon the nature of the substituent, which in turn influences the activity of the semipinacol radical. ... 

The reactions of 3-methylbutynol were first recommended by Lauron-Pernot et al. to characterize the acid-base properties of a series of metal oxides. The basic centres catalyze the cleavage reaction of MBOH, which produces acetone and acetylene, while the acid centres catalyze the dehydration of MBOH to 3-methyl-3-buten-1-yne (MBYNE) or the intermolecular rearrangement to produce 3-methyl-2-butenal (PRENAL). The production of 3-methyl-3-butene-2-one (MIPK) and 3-hydroxy-3-methyl-... 

As already discussed in section 3, 2-methyl-3-bulyn-2-ol test reaction [223] allow us to know whether a solid has acid, basic or both acid and basic pair sites. In the latter case. 3-hydroxy-3-methyi-2-butanone (HMB) and 3-methyl-3-buten-2-one (MIPK) are formed. 

Trimethyl-2-cyclohexenyl)-2-butenyl acetate. See a-lonyl acetate 1-(2,6,6-Trimethyl-2-cyclohexenyl) hepta-1,6-dien-3-one. See Allyl a-ionone 4-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-3-methyl-3-buten-2-one. See a-lsomethylionone 1-(2,6,6-Trimethyl-2-cyclohexenyl) pentan-3-one. See Dihydro-a-methyl a-ionone 1-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-1-penten-3-one... 

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