24010-93-3

Upstream product

• 140-88-5 ethyl acrylate 
• 23042-98-0 1-(cyclohex-1-en-1-yl)ethanone oxime 
• 1416255-14-5 C₁₀H₁₅NO₂ 
• 74581-96-7 (2-Methoxy-1-cyclohexen-1-yl)triphenylphosphonium-bromid 
• 75624-74-7 (3-Acetyl-2-oxocyclohexyl)triphenylphosphonium-chlorid 
• 75624-66-7 1-<2-Methoxy-3-(triphenylphosphoranyliden)-1-cyclohexen-1-yl>ethanon 
• 75624-81-6 Triphenyl(4,5,6,7-tetrahydro-3-methyl-7-benzisoxazolyl)phosphonium-chlorid 
• 874-23-7 2-acetylcyclohexanone 
• 57091-33-5 1-(1,4-dioxa-spiro[4.5]dec-6-yl)-ethanone oxime 

Downstream Products

• 33793-98-5 2-Methyl-4,5,6,7-tetrahydro-benzoxazol 

Relevant academic research and scientific papers

Rh(III)-catalyzed regioselective synthesis of pyridines from alkenes and α,β-unsaturated oxime esters

α,β-Unsaturated O-pivaloyl oximes are coupled to alkenes by Rh(III) catalysis to afford substituted pyridines. The reaction with activated alkenes is exceptionally regioselective and high-yielding. Mechanistic studies suggest that heterocycle formation proceeds via reversible C-H activation, alkene insertion, and a C-N bond formation/N-O bond cleavage process.

Haloacetylated Enol Ethers: 3. Synthesis of 3,3a,4,5,6,7-Hexahydro-3-halomethylbenzoisoxazoles

The investigation of the halomethyl group effect on the regiochemistry of the reaction of 2-acetylcyclohexanones 1a-d and β-methoxyvinyl trifluoro methyl ketone derivative 2a with hydroxylamine to afford 3,3a,4,5,6,7-hexahydro-3-halomethyl-3-hydroxybenzoisoxaloes 3a-c, and the respective dehydrated compounds 4a-c, is reported.Compounds 1a-c, 2a proved to be versatile building blocks for the regiospecific synthesis of isoxazole derivatives having a 3-halomethyl substituent, in good yields.

SYNTHESIS OF ISOXAZOLE DERIVATIVES IN REACTION OF 2-HYDROXYPHENYLCARBONYL COMPOUNDS OR 1,3-DIKETONES WITH HYDROXYLAMINE-O-SULFONIC ACID

2-Hydroxybenzaldehyde 1a and 2-hydroxyacetophenone 1b react with hydroxylamine-O-sulfonic acid (HSA) yielding the corresponding oxime hydrogensulfates 2a and 2b, separated as potassium salts.These salts undergo conversion with good yields to benzisoxazole 3a and 2-methylbenzoxazole 3b, respectively.In similar reaction of 1,3-diketones, both cyclic and acyclic 1c-k with HSA, isoxazole derivatives 3c-k were obtained.

Reactions with Organophosphorus Compounds, XLVI. Reactivity Umpolung of 1,3-Dioxo Compounds through Introduction of a Triphenylphosphonio Group. - Regioselective Syntheses of Isoxazoles and Pyrazoles from (2,4-Dioxoalkyl)triphenylphosphonium Salts

Phosphonium salts 2 and 6, upon deprotonation with BuLi and subsequent reaction with acyl halides, yield the γ-acyl derivatives 3 and 7, respectively, which on treatment with hydrochloric acid afford the corresponding (dioxoalkyl)phosphonium salts 4 and 8.Isoxazole derivatives 9 and 10 are formed regioselectivly from 4 and 8 with NH2OH*HCl, while with R-NH-NH2*HCl (R = H or C6H5) the pyrazole-containing phosphonium salts 14 and 15 are obtained in an analogous reaction.In each case the direction of cyclisation is different to the reactions of the corresponding non-phosphorus substituted 1,3-dioxo compounds.On treatment with aqueous NaOH 9 and 10 are cleaved to triphenylphosphane oxide and isoxazoles 11 and 12, while 14 and 15 yield the pyrazoles 16 and 17.Wittig reaction of 9a or 14a with aldehydes or ketones leads to the isoxazole olefins 13 or the pyrazole olefins 18, respectively.