5,7-Dimethyl-4,6-dioxo-3-methoxycarbonyl

Using an oxalic ester replaces a reactive hydrogen atom by an oxo ester (alkoxalyl) group.750 Thus diethyl 3-methyl-2-oxoglutarate is obtained in 70% yield from ethyl propionate and diethyl oxalate 751 and dimethyl dioxo-homonorcamphorate [methyl(3-methoxycarbonyl-2-oxocyclopentyl)glyoxalate] can be prepared in 90% yield from ethyl 2-oxocyclopentanecarboxylate and methyl oxalate 752... 

Cyclohexan 2-Brom-5,5-dimethyl-1,3-dioxo- E19a, 355 (H - Br) Cyclopenten /ranr-3-Brommethyl-4-methoxycarbonyl- E19a, 164 (CHBr3 -+ CH2 —Br) l-Oxa-spiro[3,5]nonan (4R, 5R )-5-Bromo-2-oxo- E21e, 4708... 

Azetidin l,4-Dimethyl-4-ethyl-3-methoxycarbonyl-2-oxo- E16b, 538 (aus 3-Diazo-2,4-dioxo-pyrrolidin)... 

Benzoyl-l-phenyl-5-methoxycarbonyl-2,3-dihydro-pyrrole-2,3-dione was reacted with 5/5-dimethyl-3-p-methoxyphenylamino-2-cyclohexen-l-one in boiling benzene to afford 6,6-d imethyl-1 -p-methoxyphenyl-2,4-dioxo-2,3,4,5,6,7-hexahydro-lH-indole-3-spiro-2-(3-benzoyl-5-oxo-4-phenyl-amino-2,5-dihydrofuran) in high yield. The reaction proceeded by the enamine addition to the 2-carbonyl group with ring opening, followed by double cyclization (06RJOC772). 

Michael addition of 5-(2-alkyl-l-methylhydrazino)-2-phenylpyridazin-3(2//)-ones to dimethyl acetylenedicarboxylate produces 5- 2-alkyl-2-[l,2-bis(methoxycarbonyl)vinyl]-l-methylhydrazi-no -2-phenylpyridazin-3(2//)-ones, which cyclize on heating in Tetralin at 220 °C by a Diels -Reese reaction68 to give methyl 3-(alkylamino)-l-methyl-2,5-dioxo-6-phenyl-l,2,5,6-tetrahy-dropyrido[2,3-rf]pyridazine-4-carboxylates l.69... 

In addition, 2-methoxycarbonyl-6-methyl-3,7-dioxobicyclo[4.4.0]dec-l-ene284. 2.6-dimethyl-3,8-dioxobicyclo[4.4.0]dec-l-ene285, and the analogous 3.10-dioxo compound 286 are reduced in high enantioselectivity to the (S)-alcohols with yeast such as tiansenula anomala, Rbodotoru-la rubra, or Kloeckera salurnus. 

C7H9NO2, 4-Acetyl-3-hydroxymethylpyrrole, 44B, 189, 1-Methylimidazolium oxalurate, 45B, 199 C7H12N2O2, 4,4-Diethy1-3,5-dioxo-1,2-pyrazolidine, 40B, 199 C7H13BrN202, 3-Methoxycarbonyl-trans-3,5-dimethyl-A -pyrazoline hydrobromide, 30b, 123... 

C17H1ftN202, 12,12-Dimethyl-2,4-dioxo-2,3,4,12-tetrahydrobenzo-[e]pyrimido[3,4-a]indole, 42B, 220 Cl7H14N2O2, 7a-Methoxycarbonyl-1,2-diaza-4,5 6,7-dibenzobicyclo-[4.3.0]non-1-ene, 43B, 362... 

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