Bailey, William F. published the artcileIntramolecular carbolithiation cascades as a route to a highly strained carbocyclic framework: competition between 5-exo-trig ring closure and proton transfer, Related Products of piperidines, the publication is Beilstein Journal of Organic Chemistry (2013), 537-543, database is CAplus and MEDLINE.
The preparation of fairly strained carbocyclic ring systems by intramol. 5-exo-trig ring closure has been well documented and the absence of proton transfers that would compromise such cyclizations is a hallmark of this chem. In an effort to explore the limitations of this approach to more highly strained systems, the preparation of a stellane (tricyclo[3.3.0.03,7]octane) framework by an intramol. carbolithiation cascade (tandem reaction) involving three coupled 5-exo-trig cyclization reactions of a vinyllithium group (I) derived from 2-bromo-4-vinyl-1,6-heptadiene by lithium-bromine exchange (substitution bromination) was investigated. The cascade does not afford 1-methylstellane. Rather, the cascade is terminated after two cyclizations by a proton transfer that occurs by an intermol. process catalyzed by trace amounts of endo-5-methyl-2-methylenebicyclo[2.2.1]heptane present in reaction mixtures as a consequence of inadvertent quenching of an intermediate alkyllithium during prolonged reaction times at room temperature The synthesis of the target compound I was achieved using 4-pentenoic acid 1,1-dimethylethyl ester as a starting material.
Beilstein Journal of Organic Chemistry published new progress about 219543-09-6. 219543-09-6 belongs to piperidines, auxiliary class Piperidine,Fluoride,Salt,Amine,Amide, name is 4-Acetamido-2,2,6,6-tetramethyl-1-oxopiperidinium Tetrafluoroborate, and the molecular formula is C11H21BF4N2O2, Related Products of piperidines.
Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem