Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: tetrahydrothiophenes

Sortuj według:

Ogranicz wyniki do:

Nowe technologie w asymetrycznej syntezie α,α-dipodstawionych α-aminokwasów

Hejmanowska J., Albrecht Ł.

Technical Issues

2016

nr 2

11--17

Optically active α,α-disubstituted α-amino acids represent a privileged structural motif present in numerous natural products and pharmacologically active molecules. These compounds have interesting biological properties owing to the presence of the quaternary stereogenic center. In recent years intensive development of methods for the synthesis of α,α-disubstituted α-amino acids has been observed. Azlactones constitute an important group of quaternary amino acid precursors that have found widespread application in organic synthesis. The aim of our work was to develop a new enantioselective methods for the synthesis α,α-disubstituted α-amino acids containing either geminal bisphosphonate, 3,4-dihydrocoumarin or tetrahydrothiophene moiety. Michael addition constitutes a key step in the developed synthetic strategies. The reactions were performed under basic conditions, using cinchona alkaloid derivatives with the proposed synthetic technologies being highly stereoselective.

Synthesis and Structure of Spirocyclic Tetrahydrothiophene Derivatives Bearing a 'Cage' Residue

Romański J., Mlostoń G., Linden A., Heimgartner H.

Polish Journal of Chemistry

2005

Vol. 79 / nr 6

973-979

Trapping of the thiocarbonyl S-methanide 4 with tetracyanoethene and N-methylmaleimide led to the [3+2]-cycloadducts 11 and 12, respectively. The structures of these cycloadducts were established by X-ray crystallography. The 1,3-dipole 4 has been generated by thermal decomposition of the corresponding 2,5-dihydro-1,3,4-thiadiazole 2, which was prepared by the 1,3-dipolar cycloaddition of diazomethane with thioketone 1.

Polycyclic [2+3]-Cycloadducts from the Thermal Decomposition of Bis(2,5-dihydro-1,3,4-thiadiazoles) in the Presence of N-Methylmaleimide

Mlostoń G., Celeda M., Linden A., Heimgartner H.

Polish Journal of Chemistry

2004

Vol.78 /nr 11-12

2089-2099