Bis methoxycarbonyl methyl

The first synthesis of a 3//-3-benzazepine, e.g. 65 (R1 = R2 = Me), was achieved by the condensation of phthalaldehyde with a bis[(alkoxycarbonyl)methyl]methylamine.24"25 With sodium methoxide as the base, A%V-bis[(methoxycarbonyl)methyl]pheiiylaniine condenses with the dialdehyde in a similar manner to give dimethyl 3-phenyl-3//-3-benzazepine-2,4-dicar-boxy late (65, Rl — Ph R2 — Me).99 However, replacement of methoxide by potassium tert-butoxide results in formation of 3-phenyl-3//-3-benzazepine-2,4-dicarboxylic acid (65, R1 = Ph R2 = H).25... 

Die Hydrodimerisierung von l,2-Bis-[2-methoxycarbonyl-vinyl]-benzol fiihrt unter Cyclisierung zum 6,12-Bis- [methoxycarbonyl-methyl]-5, t I-dimethoxycarbonyl-4b,5,6,1 Ob, 11,12-hexahydro-chrysen (29% d. Th. F 157-157,5°) neben einem Tetralin- und cincm Hexandisaure-dimelhylester-Derivat (2 0,5 0,5)2 ... 

A method for regioselective introduction of a bis(methoxycarbonyl)-methyl group into the 4-position of the piperidine skeleton was explored, and this method was applied to the preparation of cis- and rra j-2,4-disubstituted piperidines (e.g., 114) starting from 2-piperidinecarboxylic acid <96TL(37)5715>. 

The reaction of 1,2-allenyl sulfoxides with sodium malonate also afforded 2-[bis (methoxycarbonyl)methyl]-2-alkenyl sulfoxides 177, which upon further transformation would provide an efficient access to butenolide derivatives 180 [90, 91]. 

The diethyl 2-[3-bis(methoxycarbonyl)methyl-4-nitrophenyl]-2-methylmalonate obtained above,(4.13 g, 9.71 mmol) was dissolved in acetic acid (40 ml). To the solution were added water (16 ml) and concentrated sulfuric acid (4 ml), and the resulting mixture was heated for 15 hours under reflux. The acetic acid was distilled off under reduced pressure. The residue was concentrated under reduced pressure after addition of toluene. The precipitated crystals were collected by filtration and washed with water to give 2.06 g of the desired compound as a pale brown crystalline product. The filtrate and washing were combined and subjected to extraction using ethyl acetate. The ethyl acetate portion was washed successively with water and an aqueous saturated sodium chloride solution, and dried over anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to leave 0.32 g of 2-(3-carboxymethyl-4-nitrophenyl)propionic acid as a yellow crystalline product. The total amount was 2.38 g (yield 96.8%). 

With cyclohexene and silyl enol ethers, under these conditions, there was no cyclization the former gave a mixture of 3- and 4-bis(methoxycarbonyl)methyl-cyclohexenes, whereas the latter afforded RC0CH2CH(C02Me)2 (up to 60%) [24], Lactones were formed from PhI=C(C4F9)C02Et with catalysis by cupric triflate [25]. 

On heating the sulfonium ylide 464 (R = H) the isomeric bis(methoxycarbonyl)methyl-thiophene 465 is formed. Thermolysis of the ylide 464 (R = Cl) yields the thienofuran 466. When heated in the presence of copper or rhodium catalysts, 464 (R = Cl) undergoes cleavage of the carbonsulfur bond resulting in the formation of carbenoid intermediates which can trapped with activated aromatic substrates or alkenes to yield the corresponding arylmalonates or cyclopropanes, respectively. 

Bis-[methoxycarbonyl-methyl]-XIII/2b, 179f./216 (aus Keten), E4, 78 (aus Keten) (Ethoxycarbonyl-methyl)- -acetat XIII/2b, 181... 

Sulfoxid Bis-[methoxycarbonyl-methyl]- VII/4, 208 6,7,8-Trioxa-3-thia-bicyclo 3.2.11... 

Furan 3,4-Bis-[methoxycarbonyl-methyl]-2,5-dihydroxy-2,5-dihydro- E14a/1, 451 (Furan-Oxid.) a-o-Gluco-furanose 5,6-O-Carbonyl-1,2-O-isopropyliden- E4, 88/90 (H - CHO)... 

A stereoselective cyclopentaannulation of a cycloalkenone can be performed with (4/ )-[bis-(methoxycarbonyl)methyl]cyclopent-2-enone (17), a compound which is available in both individual enantiomeric forms. Palladium-catalyzed [3-1-2] cycloaddition affords high yields of the evo-products 18. 

Bis(methoxycarbonylmethyl)amme (255) gave l,4-bis(methoxycarbonyl-methyl)-3,6-dihydro-2,5(lH, 4//)-pyrazinedione (256) (EtsB or Ph llSi, PhMe, reflux, 48 h 54%) also analogues ... 

Ethyl 6-0-Acetyl-2,3,4-trideoxy-4- bis(methoxycarbonyl)-methyl -/(-D-er>-fAro-hex-2-enopyranoside 63 ... 

Bis(methoxycarbonyl)methyl -4,6-0-isopropylidene-l,2,3-trideoxy-/>-n-er> fAro-2-hexenopyranoside (38a) Typical Procedure67 ... 

---