1 -butenes, addition

The rate of addition depends on the concentration of both the butylene and the reagent HZ. The addition requires an acidic reagent and the orientation of the addition is regioselective (Markovnikov). The relative reactivities of the isomers are related to the relative stabiUty of the intermediate carbocation and are isobutylene 1 — butene > 2 — butenes. Addition to the 1-butene is less hindered than to the 2-butenes. For hydrogen bromide addition, the preferred orientation of the addition can be altered from Markovnikov to anti-Markovnikov by the presence of peroxides involving a free-radical mechanism. 

Butadiene epoxidation to epoxybutene (EpB ) was practiced at a semiworks scale of 1.4 x 10 metric tons year by Tennessee Eastman [9] between 1997 and 2004 [10]. Epoxybutene is a versatile intermediate [11] that can be used to produce a large variety of different products such as epoxybutane, 1,4-butane diols and alcohols, 1,2-butane diols and alcohols, 2,3-dihydrofuran, 2,5-dihydrofuran, tetrahydrofuran, N-methylpyrrolidone, cyclopropyl carboxyaldehyde (CPCA) derivatives, vinyl ethylene carbonate (addition of CCT to EpB), and 3,4-dihydroxy-l-butene (addition of H2O to EpB). 

Heating diethyl 2-propenylphosphonate with Et.SiH in the presence of di-tert-butylperoxide at 140°C affords diethyl 3-(triethylsilyl)propylphosphonate in low yield (21%). Under the same conditions, diethyl 4-(triethylsilyl)butylphosphonate is prepared in 63% yield from diethyl phosphite and 4-(triethylsilyl)-l-butene. Addition of (trimethylsilyl)methylmagnesium chloride to diethyl l,l-difluoro-2-oxo-2-(tert-butoxycarbonyl)etliylphosphonate in THF at low temperature results in the formation of y-silylated P-hydroxyphosphonate in 65% yield. ... 

The Ruhrchemie plant reacts propene and syngas and yields n-butyraldehyde as the desired product besides less than 4% isobutyraldehyede. The basic flow diagram of the 800000 ty 1 units is shown in Section 6.1. A smaller unit converts butenes. Additional plants are under construction. 

Predict the product of cycloaddilion of ethylene and cis-2-butene, addition being suprafacial on both the component. Is the reaction symmetry-allowed under thermal or photochemical condition ... 

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