18913-35-4

Usage

Synthesis Reference(s)

Tetrahedron Letters, 13, p. 4249, 1972 DOI: 10.1016/S0040-4039(01)94287-X

InChI:InChI=1/C5H6O2/c1-3-4-5(6)7-2/h4H,1H2,2H3

Upstream product

• 67-56-1 methanol 
• 85415-22-1 trans-2,3-dibromo-1,4-dichloro-2-butene 
• 124-41-4 sodium methylate 
• 85415-23-2 1,1,1-trimethoxy-2,3-butadiene 
• 201230-82-2 carbon monoxide 
• 106-96-7 propargyl bromide 
• 132178-16-6 Methoxyvinylketene 

Downstream Products

• 4525-28-4 methyl (E)-3-methoxybut-2-enoate 
• 90-33-5 7-hydroxy-4-methyl-chromen-2-one 
• 70758-22-4 2-Isopropenyl-3-(toluene-4-sulfonylmethyl)-but-3-enoic acid methyl ester 
• 2065-28-3 methyl 5-methyl-3-phenylisoxazole-4-carboxylate 
• 30408-26-5 methyl 4-methyl-3-phenylisoxazole-5-carboxylate 
• 30408-28-7 (3-phenyl-isoxazol-4-yl)-acetic acid methyl ester 
• 30408-27-6 methyl 2-(3-phenylisoxazol-5-yl)acetate 
• 22157-30-8 methyl (Z)-β-methoxymethacrylate 
• 110601-13-3 2-Methyl-5-methylene-3-phenyl-isoxazolidine-4-carboxylic acid methyl ester 
• 108817-72-7 2,5-dimethyl-3-phenyl-4-carbomethoxy-4-isoxazoline 
• 108817-71-6 2-methyl-5-methylene-3-phenyl-4-carbomethoxyisoxazolidine 
• 120610-21-1 2-phenyl-3,4-dimethyl-3-(carbomethoxymethyl)-5-carbomethoxy-Δ⁴-isoxazoline 
• 190272-32-3 methyl 2-phenyl-1-tosyl-2,5-dihydro-1H-pyrrole-3-carboxylate 
• 212070-71-8 2-Benzo[1,3]dioxol-5-yl-1-(toluene-4-sulfonyl)-2,5-dihydro-1H-pyrrole-3-carboxylic acid methyl ester 

Relevant academic research and scientific papers

Retro-Ene Reactions in Acylallene Derivatives

Allenic esters and amides 4 undergo a retro-ene reaction to vinylketene (6) and an aldehyde or imine (5) under the conditions of flash vacuum thermolysis (FVT). The same products are obtained by FVT of cyclobutenones 7 via electrocyclic ring opening to alkoxy- or aminovinylketenes 3 and 1,3-rearrangement of ketenes 3 to allenes 4. All the intermediates and products were characterized by matrix isolation IR spectroscopy, and in the case of 4c the reaction was also monitored by online mass spectrometry. A lower temperature for the retro-ene reaction of 4c, eliminating an imine, than for 4a, eliminating formaldehyde, is in agreement with a lower calculated activation barrier (167 and 181 kJ mol-1, respectively, at the G2(MP2,SVP) level of theory). The allenic amide 11 undergoes an analogous retro-ene reaction to the (unobserved) vinylketene 13, the latter isomerizing to cyclohexenylacrolein 16 in a 1,5-H shift (calculated barrier 125 kJ mol-1; G2 (MP2, SVP)).

CONVENIENT SYNTHESIS OF ALLENYL ESTERS AND AMIDES BY PALLADIUM CATALYZED ALKOXY- AND AMIDO-CARBONYLATION OF ALLENYL AND PROPYNYL HALIDES

Allenyl esters R1R2C=C=C(H)C(O)R (R=OMe) or amides (R=NEt2) are formed with excellent selectivities and in good yields by carbonylation of propynyl and allenyl halides at 1-20 bar CO pressure in benzene, in the presence of MeOH or HNEt2 and 1percent of Pd

METHANOLYSIS OF VICINALLY SUBSTITUTED TETRAHALOGENOBUTENES

The methanolysis of Z,E-1,2,3,4-tetrabromo-1-butene in the presence of strong bases leads predominantly to the formation of the ortho ester 1,1,1-trimethoxy-2,3-butadiene and the ether-acetal 1,1,4-trimethoxy-2-butyne.In the case of E-2,3-dibromo-1,4-dichloro-2-butene it leads predominantly to the ortho ester.During the reaction 10-12 linear unsaturated products containing 1-3 methoxyl groups are formed as side products.