Methyl vinyl ketone

About: Methyl vinyl ketone is a research topic. Over the lifetime, 1510 publications have been published within this topic receiving 26839 citations. The topic is also known as: 3-buten-2-one & gamma-oxo-alpha-butylene.

γ‐Radiolysis of ketone polymers. II. γ‐Irradiation of styrene–methyl vinyl ketone copolymers

Abstract: γ-Radiolysis of copolymers of styrene and methyl vinyl ketone shows that the introduction of pendant carbonyl groups markedly increases the G(s) value as compared to the homopolymer of styrene. The G(x) value is only slightly affected. These efficiencies are determined by employing an established statistical theory for random crosslinking and scission coupled with gel-permeation chromatography as the analytical tool required to follow the changes in the MWD of polymers. Also the G(H2) values are unaltered by the introduction of carbonyl groups in polystyrene. These results are in marked contrast to the effects of carbonyl groups in polyethylene when subjected to γ-radiolysis and can be attributed to the protective role played by the aromatic phenyl groups in polystyrene.

Synthesis of Poly-substituted 2-Pyridones via (3+2+1) Annulation Protocol from Baylis-Hillman Adducts

Abstract: The synthesis of a substituted 2-pyridone ring is an area of continuing interest due to its abundance in many biologically important compounds containing this moiety. Although numerous papers have been reported on the synthesis of this class of compounds, development of a new and efficient synthetic procedure is still required. Recently, we reported an efficient synthetic method for poly-substituted pyridines from the combination of BaylisHillman adducts (3 carbons), activated methylene compounds (2 carbons) and ammonium acetate (1 nitrogen) via [3+2+1] annulation protocol in good yields, regioselectively. In the previous paper, we used Baylis-Hillman adducts derived from methyl vinyl ketone and obtained 2methyl pyridine derivatives. In continuation of our research, we intended to prepare the valuable poly-substituted 2pyridones by using the Baylis-Hillman adducts of methyl acrylate 1a as shown in Scheme 1. The starting material 3a was synthesized from the reaction of Baylis-Hillman acetate 1a and methyl acetoacetate (2a) in 77% yield. The ester 3a indeed produced 2-pyridone 7a, albeit in low yield (16%), along with three other products, 4a (34%), 5a (7%) and 6a (5%), when subjected to the conditions previously employed for the synthesis of pyridine derivatives (NH4OAc (3.0 equiv)/AcOH/reflux). Increasing the reaction temperature or varying the solvent (propionic or butyric acid) did not improve the results. The use of NH4Cl or NH4OH was also not effective. Fortunately, during the examinations we found that the use of excess amounts of NH4OAc afforded good yield of 7a. The reaction gave much better yield of 7a (75%), while suppressing the formation of by-products 4a (4%), 5a (12%) and 6a (5%), when 3a was heated in AcOH with 20 equiv of NH4OAc. The use of excess amounts of NH4OAc might be beneficial for the isomerization of 4a to 7a, although the reason is not clear at this stage. Encouraged by the results we prepared starting materials 3b-g similarly from ethyl acetoacetate (2b), 2,4-pentanedione (2c), methanesulfonylacetone (2d), 1,3-cyclohexanedione (2e), deoxybenzoin (2f), and 1,3-indandione (2g) in 56-85% yields. The syntheses of 7b-g were carried out by the same method for 7a and the results are summarized in Table 1. Various 2-pyridone derivatives 7b-g were synthesized in 64-82% yields including bicyclic (entry 5) and tricyclic compound (entry 7). In all cases trace amounts of the corresponding benzylidene compounds, alcohols, and benzoyl derivatives were observed on TLC, but we didn’t isolate them except entry 1 (vide supra, Scheme 1). The formation of alcohol 5a and benzoyl derivative 6a could be explained

Synthesis and 13C nuclear magnetic resonance assignments of cannithrene 1: a cannabis constituent

Abstract: Two synthetic approaches to cannithrene 1 (1) have been explored. One-pot annelation of 6,8-dimethoxytetralone by first forming a β-keto sulfoxide, then addition of methyl vinyl ketone, gave, unexp...

1,4-Thiazepines and 1,4-thioxans from thiols

Abstract: Methyl vinyl ketone and 2-mercaptoethylamine react under basic conditions to yield a 1,4-thiazepine. Cyclisation of products from reaction of thioglycollic acid with 1,2-epoxides yield substituted 1,4-thioxans.

Process for the production of epoxides

Abstract: 1,209,321. Epoxides. IMPERIAL CHEMICAL INDUSTRIES Ltd. 17 June, 1968 [29 June, 1967], No. 30023/67. Heading C2C. A process for the production of epoxides comprises contacting an olefinic compound in a liquid phase with oxygen, a catalyst which comprises Cr, Ti, Zr, Hf, V, Nb, Ta, Mo, W, Re, Th or U or a compound thereof and either (a) hydrogen and a diketone containing the functional groups: -CO-CO- or -CO-(X)-CO- in which X represents a -CHR- or -CR = CR- group in which R is a phenyl or alkoxyphenyl group, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or hydrogen or X represents a group in which R 1 , R 2 , R 3 and R 4 are hydrogen, alkyl, cycloalkyl or alkoxy groups or (b) a reduced form of such a diketone in which at least one of the CO groups has been reduced to a C-OH group. Suitable olefinic compounds are ethylene, propylene, a butene, cyclohexene, butadiene, styrene, allyl alcohol, methyl vinyl ketone and allyl and vinyl acetate. The metal catalyst is preferably in the form of a compound soluble in the liquid phase, e.g. as a carbonyl, naphthenate or stearate or the metal catalyst and diketone may be supplied together as a complex. Suitable diketones include benzoquinone, anthraquinone, duraquinone, 2-ethyl or 2-tert.-butyl anthraquinone and acetylacetone. The preparation of 1,2-epoxy octane is described using chromium acetylacetonate and using molybdenum carbonyl and a reduced form of 2-ethyl anthraquinone.