Butyl fumarate

Polyfumarates. Because of steric hindrance, fumarates are difficult to polymerize into high molecular-weight polymers. However, it was demonstrated during the early 1980s that bulky fumarates, such as di-/-butyl fumarate, 0 2 200 [7633-38-7] (3), can be polymerized thermally into high... 

Figure 3.39. Scope of Rh/chiral diene-catalyzed asymmetric 1,4-addition of arylboronic acids to di-rert-butyl fumarate.

This rearrangement has been reviewed,3 so only results published since 1968 will be discussed herein. In addition to ring contraction, it is noteworthy that cyclobutylidenes are also able to undergo 1,3-dipolar cycloaddition to 1,1-diethoxyethene,4 tert-butyl fumarate,4 styrenes5 and but-2-yne,6 yielding spiro[2.3]hexane derivatives. Intramolecular trapping of cyclobutylidene by alkenes is also known.7... 

Not only Diels-Alder cycloadditions but also 1,3-dipolar cycloaddition reactions can be subject to hydrophobic rate enhancements. For example, the reaction of C,N-diphenylnitrone with di-n-butyl fumarate at 65 °C to yield an isoxazolidine is about 126 times faster in water than in ethanol, while in nonaqueous solvents there is a small 10-fold rate decrease on going from n-hexane to ethanol as solvent - in agreement with an isopolar transition-state reaction [cf. Eq. (5-44) in Section 5.3.3] [858]. Because water and ethanol have comparable polarities, the rate increase in water cannot be due to a change in solvent polarity. During the activation process, the unfavourable water contacts with the two apolar reactants are reduced, resulting in the observed rate enhancement in aqueous media. Upon addition of LiCl, NaCl, and KCl (5 m) to the aqueous reaction mixture the reaction rate increases further, whereas addition of urea (2 m) leads to a rate decrease, as expected for the structure-making and structure-breaking effects of these additives on water [858]. 

Monomers. MA was purified by multiple recrystallizations and/ or subliniation. The monomer N-phenylmaleimide was prepared by a known procedure (13) and recrystallized several times to obtain high purity. Treatment of cis-2-butene-l,4-diol with a two-fold molar excess of acetic anhydride for 6 hr. at 100°C was the method of choice to prepare cis-2-butene-l,4-diol diacetate, bp 55-60°C/ 0.1mm [lit. 120-l°C/18mm (28)1). Dimethyl maleate and di-ti-butyl fumarate were dried over sodium sulfate and distilled. The cis-2-butene-l,4-diol starting material contained ca. 8% trans isomer, as shown by NMR. 

As background information, an attempt was made to copolymerize cis-2-butene-l,4-diol diacetate with MA. Heating equimolar mixtures of the two monomers with AIBN (2 wt%) for 15 hr. at 75°C produced only a very low yield (<10%) of polymeric material. Using the same conditions, equimolar mixtures of IA-di-t-butyl fumarate and IA-dimethyl maleate gave only a trace of copolymer. Yokayama and Hall (10) also repored that diethyl maleate and diethyl fumarate undergo free-radical copolymerization with IA to give very low yields of non-equimolar copolymer. 

Beilstein Handbook Reference) AI3-09505 BRN 1726635 2-Butenedioic acid (2E)-, dibutyl ester 2-Butenedioic acid, dibulyl ester, (E)- Butyl fumarate Dibutyl fumarate Dibutylester kyseliny fumarove EINECS 203-327-9 Fumaric acid, di-n-butyl ester Fumaric acid, dibutyl ester NSC 140 RC Comonomer DBF Stafex DBF Staflex DBF. Used In monomeric plasticizers copolymers and as a chemical intermediate. Liquid mp = -13.5 bp n 285 , bp4 " 150° d = 0.9775 insoluble in HaO, soluble in CHCI3, MeaCO. AC Ind. Inc. Monomer-Polymer Dajac Penta Mfg. Unitex. 203-327-9... 

SCHEME 32 Synthesis and deprotection of a t-butyl fumarate derivative. 

Synonyms Di-n-butyl fumarate Fumaric acid, dibutyl ester Empirical C12FI20O4... 

Di-n-butyl fumarate. See Dibutyl fumarate Di-n-butyl-glycerol diether. See 1,3-Dibutoxy-2-propanol... 

Crivello IV, Shim SY (1994) Photoresist composition comprising a copolymer having a di-t-butyl fumarate. US Patent 5,346,803... 

Fumarate, di-tert-butyl Fumarate, bis(3-[tris(trimethylsiloxy) 0.61 0.21 1040... 

---