1,3-Butadiene → 5,6-Dimethyl-3a,4,7,7a-tetrahydro-2-benzofuran-1,3-dione
Reaction equation
[C:1]1(=[O:7])[O:6][C:4](=[O:5])[CH:3]=[CH:2]1.C=CC=C.[C:12]1(=O)O[C:15](=O)[C@H:14]2[CH2:18]C=C[CH2:21][C@@H:13]12.[OH-].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2]>C1C=CC=CC=1.O1CCOCC1.[N+](C)([O-])=O>[CH3:12][C:13]1[CH2:21][CH:2]2[CH:3]([CH2:15][C:14]=1[CH3:18])[C:4](=[O:5])[O:6][C:1]2=[O:7]Participants
Reactant 4
Product 1
Reagents, catalysts & solvents 3
Procedure
As shown above in 2.1.2 to 2.4.2 maleic acid anhydride is reacted with a suitable conjugated diene compound to give the wanted Diels-Alder reaction product. For example maleic acid anhydride reacted with butadiene in benzene or dioxane at ambient temperature is quantatively transferred to cis-1,2,3,6-tetrahydrophthalic acid anhydride (K. Alder et al, Liebigs Annalen der Chemie, 460, 98 (1928) and 514, 1 (1934)). In the reaction of maleic acid anhydride with 2,3-dimethyl-1,3-dibutadiene in nitromethane and addition of 5 mol % of a rhuthenium catalyst on a hydroxyl apatite support, 5,6-dimethyl-3a,4,7,7a-tetrahydro-isobenzofurane-1,3-dione is formed (K. Mori et al. JACS 125, 11460 (2003)). 4,10-dioxatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione is formed by reacting maleic acid anhydride with furane in diethylether. First the kinetically faster endo-product is formed which during 8 h at ambient temperature completely rearranges to the thermodynamically stable exo-product (R. B. Woodward and H. Baer, JACS 70 1161 (1948)). Maleic acid anhydride and 1,3-cyclohexadiene in benzene with heating at ambient temperature quantitatively react to 4-oxatricyclo[5.2.2.02,6]undec-8-ene-3,5-dione.
Workup
- customto give
- customthe wanted Diels-Alder reaction product
Sources & evidence
- ORD record
- ord-6f56f63be088452b978ae78b2597662f
- Source dataset
- uspto-grants-2015_12
- Patent number
- US09199934B2
Reaction notes
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