dimethyl (E)-but-2-enedioate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl hydrazine (12 ml, 228 mmol) was added dropwise to dimethyl fumarate (32.8 g, 228 mmol) at −5° C. The mixture was stirred under warming to rt for 16 h and then heated to 100° C. for 3 h. The crude reaction product (36 g, quantitative) was used for the next step without purification. [[M+H]+=159.1] heated to 100° C. for 3 h The crude reaction product (36 g, quantitative) was used for the next step without purification

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3-dimethylbutadiene (9.84 g, 0.12 mol) and dimethyl fumarate (14.4 g, 0.1 mol) were stirred together in toluene (40 ml) at 50° C. for 24 hr. The solvent was removed in vacuo and the solid residue recrystallised from diethyl ether, to give the title compound in 85%, yield. N.m.r: δH (90 MHz, CD3OD) 3.71 (s,6H), 2.55 (m,2H), 2.10 (m,4H), 1.74 ppm (s,6H). The solvent was removed in vacuo the solid residue recrystallised from diethyl ether

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3-dimethylbutadiene (9.84 g, 0.12 mol) and dimethyl fumarate (14.4 g, 0.1 mol) were stirred together in toluene (40 ml) at 50° C. for 24 hr. The solvent was removed in vacuo and the solid residue recrystallised from diethyl ether, to give the title compound in 85%, yield. N.m.r: δH (90 MHz, CD3OD) 3.71 (s,6H), 2.55 (m,2H), 2.10 (m,4H), 1.74 ppm (s,6H). The solvent was removed in vacuo the solid residue recrystallised from diethyl ether

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The dimethyl fumarate (1224 g, 8.5 mol) and water (4000 ml) were added to a 6-liter flask and irradiated by 365 nm ultraviolet lights at a temperature from 5 to 7° C. for 7 hours. The resultant solid in the flask was vacuum filtered to obtain tetramethyl cyclobutane-1,2,3,4-tetracarboxylate (1224 g, 4.25 mol). According to the NMR spectrum as shown in FIG. 1, dimethyl fumarate was present before the cyclization reaction. It can be observed from FIG. 2 that, after the cyclization reaction, the absorption peak at 6.77 ppm disappeared which means that dimethyl fumarate had been reacted completely. The absorption peak at 3.68 ppm represents the generation of the corresponding cyclobutanetetracarboxylate. FIGS. 1 and 2 prove that the yield of the reaction is almost 100%. irradiated by 365 nm ultraviolet lights at a temperature from 5 to 7° C. for 7 hours filtered

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The dimethyl fumarate (1224 g, 8.5 mol) and water (4000 ml) were added to a 6-liter flask and irradiated by 365 nm ultraviolet lights at a temperature from 5 to 7° C. for 7 hours. The resultant solid in the flask was vacuum filtered to obtain tetramethyl cyclobutane-1,2,3,4-tetracarboxylate (1224 g, 4.25 mol). According to the NMR spectrum as shown in FIG. 1, dimethyl fumarate was present before the cyclization reaction. It can be observed from FIG. 2 that, after the cyclization reaction, the absorption peak at 6.77 ppm disappeared which means that dimethyl fumarate had been reacted completely. The absorption peak at 3.68 ppm represents the generation of the corresponding cyclobutanetetracarboxylate. FIGS. 1 and 2 prove that the yield of the reaction is almost 100%. irradiated by 365 nm ultraviolet lights at a temperature from 5 to 7° C. for 7 hours filtered

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Using the nano-RuHAP catalyzed protocol, alkenes were selectively converted into corresponding cis-1,2-diol with moderate to good yields (see TABLE 1). α,β-unsaturated alkenes such as ethyl trans-cinnamate, ethyl crotonate, dimethyl fumarate, dimethyl maleate and isophorone can be transformed to their corresponding cis-1,2-diols in 70, 65, 53, 50 and 64% isolated yields, respectively (entries 1-5). Under the Ru-catalyzed conditions, effective oxidations of styrene and 1-dodecene gave styrene glycol (85%) and dodecene glycol (75%) in good yields (entries 6 and 7). Likewise, dihydroxylation of 1,2-disubstituted alkenes including 1,4-diacetoxy-cis-but-2-ene and phenanthrene has been achieved to afford the corresponding cis-1,2-diols in 61 and 60% yields (entries 8 and 9). Using 1-acetoxy cyclohex-2-ene as substrate, the Ru-catalyzed dihydroxylation furnished 1-acetoxy-2,3-dihydroxycyclohexane in 75% yield (entry 10) with the anti-isomer being the major product (anti:syn=9:1). Yet, the catalytic dihydroxylation of trisubstituted alkenes such as (3-benzloxy)-1-methylbut-1-ene appeared to be less effective, and the corresponding cis-1,2-diol was obtained in only 45% yield (entry 11). to good yields (see TABLE 1) isolated yields

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1.06 g (7.34 mmol) of dimethyl fumarate in 20 mL of dry 1,2-dichloroethane under nitrogen atmosphere, was added with stirring, 7.34 mmol of a 1.0 M solution of ethylaluminum dichloride in hexane. The resultant yellow solution was heated to reflux and a solution of 1.0 g (7.34 mmol) of phenyl vinyl sulfide in 4 mL of dry 1,2-dichloroethane was added dropwise, via syringe, over a period of 20 minutes. The reaction mixture was allowed to stir at reflux for 3 h. After cooling to ambient temperature, the reaction was quenched carefully with 100 mL of 1.0 N hydrochloric acid solution and the reaction mixture was extracted with 3×50 mL of ethyl acetate. The organic extract was washed with 2×50 mL of water and 50 mL of brine, dried over anhydrous magnesium sulfate, filtered and concentrated to a viscous orange oil. The oil (1.56 g) was chromatographed on silica gel (25 g) eluted with 300 mL of 3% ethyl acetate in 1,2-dichloroethane. The resultant yellow oil was purified by bulb-to-bulb distillation to give the title compound as a yellow oil; b.p 120° C. (0.05 mm Hg); EI-MS, m/e (relative intensity): 280 (M+, 18), 136 (100), 91 (13); 1H NMR (CDCl3) δ 2.20 (q, 1H), 2.61 (m, 1H), 3.22 (q, 1H), 3.34 (t, 1H), 3.66 (s, 3H), 3.67 (s, 3H), 3.87 (m, 1H), 7.30 (m, 5H). The resultant yellow solution was heated to reflux to stir at reflux for 3 h the reaction was quenched carefully with 100 mL of 1.0 N hydrochloric acid solution the reaction mixture was extracted with 3×50 mL of ethyl acetate The organic extract was washed with 2×50 mL of water and 50 mL of brine dried over anhydrous magnesium sulfate filtered concentrated to a viscous orange oil The oil (1.56 g) was chromatographed on silica gel (25 g) eluted with 300 mL of 3% ethyl acetate in 1,2-dichloroethane The resultant yellow oil was purified by bulb-to-bulb distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl hydrazine (12 ml, 228 mmol) was added dropwise to dimethyl fumarate (32.8 g, 228 mmol) at −5° C. The mixture was stirred under warming to rt for 16 h and then heated to 100° C. for 3 h. The crude reaction product (36 g, quantitative) was used for the next step without purification. [[M+H]+=159.1] heated to 100° C. for 3 h The crude reaction product (36 g, quantitative) was used for the next step without purification

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3-dimethylbutadiene (9.84 g, 0.12mol) and dimethyl fumarate (14.4 g, 0.1 mol) were stirred together in toluene (40 ml) at 50° C. for 24 hr. The solvent was removed in vacuo and the solid residue recrystallised from diethyl ether, to give the title compound in 85% yield. N.m.r: δH (90 MHz, CD3OD) 3.71 (s,6H), 2.55 (m,2H), 2.10 (m,4H), 1.74 ppm (s,6H). The solvent was removed in vacuo the solid residue recrystallised from diethyl ether

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Dimethyl fumarate (781 mg; 1.1 eq.) was added to 5-ethoxyoxazole (557.3 mg; 4.9 mmol), and the mixture was reacted at 120° C. for 1.5 hours. The reaction residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane 2:1), to give crude crystals of the title compound. Yield: 730 mg (70.2%). The crude crystals were recrystallized from dichloromethane-hexane, to give colorless plates. the mixture was reacted at 120° C. for 1.5 hours The reaction residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane 2:1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 1.06 g (7.34 mmol) of dimethyl fumarate in 20 mL of dry 1,2-dichloroethane under nitrogen atmosphere, was added with stirring, 7.34 mmol of a 1.0 M solution of ethylaluminum dichloride in hexane. The resultant yellow solution was heated to reflux and a solution of 1.0 g (7.34 mmol) of phenyl vinyl sulfide in 4 mL of dry 1,2-dichloroethane was added dropwise, via syringe, over a period of 20 minutes. The reaction mixture was allowed to stir at reflux for 3 h. After cooling to ambient temperature, the reaction was quenched carefully with 100 mL of 1.0 N hydrochloric acid solution and the reaction mixture was extracted with 3×50 mL of ethyl acetate. The organic extract was washed with 2×50 mL of water and 50 mL of brine, dried over anhydrous magnesium sulfate, filtered and concentrated to a viscous orange oil. The oil (1.56 g) was chromatographed on silica gel (25 g) eluted with 300 mL of 3% ethyl acetate in 1,2-dichloroethane. The resultant yellow oil was purified by bulb-to-bulb distillation to give the title compound as a yellow oil; b.p 120° C. (0.05 mm Hg); EI-MS, m/e (relative intensity): 280 (M+, 18), 136 (100), 91 (13); 1H NMR (CDCl3) δ2.20 (q, 1H), 2.61 (m, 1H), 3.22 (q, 1H), 3.34 (t, 1H), 3.66 (s, 3H), 3.67 (s, 3H), 3.87 (m, 1H), 7.30 (m, 5H). The resultant yellow solution was heated to reflux to stir at reflux for 3 h the reaction was quenched carefully with 100 mL of 1.0 N hydrochloric acid solution the reaction mixture was extracted with 3×50 mL of ethyl acetate The organic extract was washed with 2×50 mL of water and 50 mL of brine dried over anhydrous magnesium sulfate filtered concentrated to a viscous orange oil The oil (1.56 g) was chromatographed on silica gel (25 g) eluted with 300 mL of 3% ethyl acetate in 1,2-dichloroethane The resultant yellow oil was purified by bulb-to-bulb distillation

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3-dimethylbutadiene (9.84 g, 0.12mol) and dimethyl fumarate (14.4 g, 0.1 mol) were stirred together in toluene (40 ml) at 50° C. for 24 hr. The solvent was removed in vacuo and the solid residue recrystallised from diethyl ether, to give the title compound in 85% yield. N.m.r: δH (90 MHz, CD3OD) 3.71 (s,6H), 2.55 (m,2H), 2.10 (m,4H), 1.74 ppm (s,6H). The solvent was removed in vacuo the solid residue recrystallised from diethyl ether