Synthesis of Substituted Pyrrolidines and Pyrrolizidines

The Indolizidine Alkaloids

“…-The synthesis of racemic 147 (106) was accomplished by one of the methods employed for the synthesis of septicine (7) (78). The hydroxymethylene derivative of ethyl 4-methoxyphenylacetate was reduced by sodium borohydride to the hydroxy-ester and converted to its chloride which gave 152 on condensation with ethyl 2-pyrrolidinyl acetate (107,108). Dieckmann condensation of 152 (R = H), followed by hydrolysis and decarboxylation, yielded the indolizidone 153 (R = H), which was reduced to the carbinol 154 by methyl lithium.…”

Rearrangement of pyruvates to malonates. Synthesis of .beta.-lactams

“…Initially 7 was obtained according to the published procedure. 11 We then planned to make 7-substituted derivatives, e.g., 13, by alkylation of 7 with methyl iodide, but alkylation under a variety of conditions (sodium hydride in tetrahydrofuran or dimethylformamide, thallous ethoxide in benzene) gave exclusively the O-alkylated product. Similar resistance to C-alkylation was apparently encountered and circumvented by condensation of substituted pyruvic acids or oxalacetates with an imine.8…”

Poisoning and Reuse of Supported Precious Metal Catalysts in the Hydrogenation of N-Heterocycles, Part II: Hydrogenation of 1-Methylpyrrole over Rhodium

“…Rhodium is often used in the heterogeneous catalytic hydrogenation of pyrroles, typically in a supported form: on activated carbon [24][25][26][31][32][33][34][35], on alumina [24,25,34,[36][37][38][39][40][41][42], or on silica [43]. For instance, 2,5-dimethylpyrrole was reduced to cis-2,5-dimethylpyrrolidine over 5% Rh/Al 2 O 3 (7% by weight of substrate) in acetic acid, at 3 bar and room temperature, with 70% yield [36].…”