L,4-dihydroxy-2-butene

Durairaj et al. (2) prepared unsaturated novolaks, (I), using resorcinol, formaldehyde, and l,4-dihydroxy-2-butene with p-toluene sulfonicacid as catalyst that contained 8.7% tetramer. 

Endosulfan [115-29-7] (36) is the adduct of hexachlorocyclopentadiene and l,4-dihydroxy-2-butene which reacts subsequently with SOCl to produce 6>7>8>9>10>10-hexachloro-l,5,5, 6,9,9 -hexahydro-6>9-methano-2,4,3-benzodioxathiepin-3-oxide. The technical product is a brownish solid (mp 70— 100°C, vp 1.3 mPa at 30°C) which consists of about four parts of a-isomer (mp 108°C, cis with regard to the sulfite group) and one part of the p-isomer (mp 206°C, trans with regard to the sulfite group). The a-isomer, which is somewhat more insecticidal, is slowly converted to the more stable p-isomer at high temperature, and both isomers are oxidized slowly to endosulfan sulfate [1031-07-8] (mp 181°C). In acid media, both isomers form endosulfan diol [2157-19-9] (mp 203°C). The rat LDc-s are 43, 18 (oral) and 130, 74 (dermal) mg/kg. Endosulfan is a broad-spectrum insecticide for vegetables, fruits, and row crops. Unlike the other cyclodiene insecticides, it is biodegradable by hydrolysis at the sulfite ester bonds. 

Methyl-l H-pyrazole werden aus l,4-Dihydroxy-2-buten oder 3-Hydroxy-l-alkinen mit Hydrazin bzw. substituierten Hydrazinen in 80%iger Schwefelsaure und in Gegenwart von Iod oder Iodiden gebildet, z. B. entsteht aus 1,4-Dihydroxy-2-buten und Hydrazin 3 (5)-Methyl-1 H-pyrazol (69%)2411. 

As shown in Figure 12, the hydrogenation of l,4-dihydroxy-2-butyne (ByD) occurs stepwise via formation of the l,4-dihydroxy-2-butene (BeD) to the desired product 1,4-butanediol (BDO). Table 6 displays the trickle phase reaction data for the catalysts studied here at 135°C and 60 bar. The use of higher pressures and lower temperatures (e.g., 266 bar and 75°C (31)) would provide higher selectivi-ties, however the conditions used here were chosen to make the reaction more demanding so that we could better differentiate between the various catalysts. 

Use of erythritol begins to explore the factors that control regiochemistry of the catalytic reaction. Here, cyclocondensation can lead to either a 1,2-diolate (Scheme 4 terminal ) or a 2,3-diolate ( internal ). The former will produce 3,4-dihydroxy-1-butene, while the latter will produce l,4-dihydroxy-2-butene (presumably as the cis isomer). Secondary reduction of the terminal product will also produce 1,3-butadiene. 

The rate of l,4-dihydroxy-2-butyne hydrogenation was determined in the trickle phase with a 120-ml tubular reactor using 40 ml of either 3-mm activated tablets or hollow spheres. This hydrogenation was performed at 60 bar hydrogen pressure, 135°C, and the LHSV values of 0.80 and 1.6 h with a 50 wt.% 1,4-dihydroxy-2-butene aqueous solution whose pH was adjusted to 7 with NaHC03. 

Dihydroxy-trans-buten-(2)i / -Hydroxy-cis-2-methyl-buten-(2) 4 5-Hydroxy-pemadien-(l, 3)5 1-Hydroxy-cis -buten-(2)6 5-Hydroxy-4-methyl-pentin-(l )7 / -Hydroxymethyl-cyclohepten8 1-Hydroxy-1-hexadien-(2,4)9... 

Unklar ist der EinfluG polarer Atomgruppen im Molekiil auf die Stereochemie bei der partiellen Hydrierung. Acetylendicarbonsaure und l,4-Dihydroxy-butin-(2) werden im alkalischen im wesentlichen zu Fumarsaure bzw. trans-1,4-Dihydroxy-buten-(2) redu-ziert1. 

So erhalt man z.B. aus l,4-Dihydroxy-butin-(l) mit Raney-Nickel (2071 bar) 66% d.Th. eincscishrans-1,4-Dihydroxy-buten-(2)-Gemisches und 8,5% d. Th. 2,5-Dihydro-furan, das aus der rw-Komponente entstan-den ist7-10. 

The ratio of [(1,4-butanediol) / (l,4-dihydroxy-tra/is-2-butene + l,4-dihydroxy-cis-2-butene)] ° The ratio of 1,4-dihydroxy-< is-2-butene to 1,4-dihydroxy-tra s-2-butene " HS = Hollow Spheres... 

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). 

Mit praparativ interessanten Ausbeuten erfolgt auch die Umlagerung der 3,4-Dihydroxy- 1,2,5,6-tetraalkyl-l,5-hexadiene20-22. Je nach Reaktionsbedingungen werden dabei Derivate des 2-Vinyl-2-butenals bzw. 2-Vinyl-3-butenals erhalten (s. Tab. 110, S. 544). Ebenso fiihren 1,6-Dialkyl- bzw. -Diaryl-3,4-dihydroxy-1,5-hexadiene vorzugsweise zu Aldehyden23. 

Mild oxidation of tetramethylcyclobutadienenickel chloride (XIV) with aqueous sodium nitrite gave as-3,4-dihydroxy-l,2,3,4-tetramethylcyclo-butene (LXIV) and was the first chemical proof of the presence of a cyclobutadiene ring in (XIV) (32). 

Percent product distribution butanone 80.8 1.46, 2-hydroxy-2-methyl-butanal 4.6 0.1, l,2-dihydroxy-2-methyl-butane 14.3 0.3. The addition of OH at the double bond of 2-methyl-1-butene occurs to 10.5 % at the inner and to 89.5 % at the outer position. This results mainly in the formation of a tertiary hydroxyalkyl peroxy radical, which carries no abstractable hydrogen at the... 

Didehydro [159686-28-9]. l-[2,4-Dihydroxy-3- 2-hydroxyethy[)-6-methoxyphenyl]-2-buten-l-one CisHiA M 252.266 Metab. of P. etheridgei. Isol. as tri-Ac. 

A more straightforward access to glycocitrine-II (25) was described by Grundon and Reisch, through direct C-alkylation of 1,3-dihydroxy-lO-methylacridone (19) with one equivalent of the readily available l-bromo-3-methyl-2-butene (281), in tetrahydrofriran at 20°C, in the presenee of alumina in order to prevent O-alkylation (326). The isomeric l,3-dihydroxy-10-methyl-2-(3-methyl-2-butenyl)-acridone (282) and the dialkylated l,3-dihydroxy-10-methyl-2,4-bis(3-methyl-2-butenyl)-acridone (283) were also formed during the reaction. Excess of alkylating agent resulted in the formation of tetracyclic compounds 284 and 285. 

Wahrend in Boratpuffer-Losung (pH 9,3) Buten-(2)-al bei -1,5 V an Quecksilber selek-tiv zu l-Hydroxy-buten-(2) reduziert wird, erhalt man in Acetatpuffer-Losung (Leitsalz Lithiumchlorid pH 4,7) bei -1,2 V 4,5-Dihydroxy-octadien-(2,6)9. 

Sjoblom, T. Lahdetie, J. (1996) Micronuclei are induced in rat spermatids in vitro by 1,2,3,4-diepoxybutane but not by l,2-epoxy-3-butene and 1.2-dihydroxy-3,4-epoxybutane. Mutagenesis, 11, 525-528... 

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