1,1-Nitroethylene derivs synthesis

Other methods of generating a-aminoketones in situ are common, if somewhat less general than the methods already described. 2-Nitrovinylpyrrolidine, which is readily available, yields 2,3-bis(3-aminopropyl)pyrazine on reduction and this almost certainly involves ring opening of the intermediate enamine to an a-aminoketone which then dimerizes under the reaction conditions (Scheme 59) (78TL2217). Nitroethylene derivatives have also served as a-aminoketone precursors via ammonolysis of the derived epoxides at elevated temperatures (Scheme 60) (76S53). Condensation of 1,1-disubstituted hydrazine derivatives with a-nitro-/3-ethoxyethylene derivatives has been used in the synthesis of l,4-dialkylamino-l,4-dihydropyrazines (Scheme 61) (77S136). 

Lithium diorganocuprates Synthesis of aliphatic nitro compds. from 1,1-nitroethylene derivs. 

Stannous chloride Synthesis of oximes C G (NOg) from 1,1-nitroethylene derivatives via 1,2-chloroximes s. 16, 600 SnCl2 GGlG( NOH)... 

Aliphatic nitro compds. from 1,1-nitroethylene derivs. s. 24, 62 one-pot synthesis of higher from lower nitroalkanes and 0x0 compds. cf. G. B. Bachman and R. J. Maleski, J. Org. Chem. 37, 2810 (1972)... 

Apparently, the synthesis of 3-cyanoisoxazoline-2 N-oxide from diazomethane and cyanodinitromethane derivatives also occurs through cycloaddition of diazomethane to intermediate 1-cyano-l-nitroethylene (84). 

Another strategy for the synthesis of lycorine commenced with the Diels-Alder reaction of l-methylenedioxyphenyl-2-nitroethylene with butadiene to provide the cyclohexene derivative 85, which on reaction with MCPBA gave 86 together with the diastereomeric epoxide (1 1) (Scheme 6) (112). Hydrogena-... 

The next series of syntheses is based on conjugate additions. A 2-arylcyclo-hexanone was regio- and stereoselectively added to nitroethylene to access the octahydroindole core present in the alkaloids. This has enabled the total synthesis of (+j-y-lycorane and (+)-crinane (280). Tomioka described a chemoselective conjugate addition - nitro Michael reaction sequence to prepare a- and -lycoranes in their racemic form (281). The addition of an arylcuprate to a D-mannitol-derived... 

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