Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: 1,3-oxathioles

Sortuj według:

Ogranicz wyniki do:

Reaction of 2,2,4,4-Tetramethyl-3-thioxocyclobutanone with Dimethyl Diazomalonate Catalyzed by Rh2(OAc)4

Mlostoń G., Romański J., Heimgartner H.

Polish Journal of Chemistry

2002

Vol. 76 / nr 4

551-555

The reaction of 2,2,4,4-tetramethyl-3-thioxocyclobutanone (1) with dimethyl diazomalonate in the presence of Rh2(OAc)4 in toluene at 50_C yielded a mixture of three products 10, 11, and 12. Thiocarbonyl ylide 8 is believed to be the common intermediate. The formation of 10 is rationalized by the 1,3-dipolar electrocyclization of 8 to give spirocyclic thiirane 9, which spontaneously eliminated sulfur. On the other hand, the 1,5- dipolar electrocyclization of 8 led to 1,3-oxathiole 11, which is converted into lactone 12 by hydrolysis.