Enantio- and diastereoselective construction of 4,9-dimethylspiro[4.4]nonane-2,7-dione using Rh-catalyzed asymmetric cyclization

Autor:	Masakazu Tanaka, Kiyoshi Sakai, Hiroshi Suemune, Masanori Imai, Akiko Matsui, Kazuhisa Funakoshi, Masakazu Fujio, Eishi Sakamoto, Miyuki Takahashi
Rok vydání:	2001
Předmět:	Organic Chemistry Cationic polymerization Diastereomer chemistry.chemical_element Optically active Biochemistry Medicinal chemistry Rhodium Catalysis chemistry.chemical_compound chemistry Drug Discovery Nonane Quaternary carbon BINAP
Zdroj:	Tetrahedron. 57:1197-1204
ISSN:	0040-4020
DOI:	10.1016/s0040-4020(00)01106-6
Popis:	Asymmetric cyclization using Rh-complexes was applied to the synthesis of 4,9-dimethylspiro[4.4]nonane-2,7-diones. The spiro[4.4]nonane skeleton bearing a chiral quaternary carbon could be stepwisely constructed by using Rh-catalyzed cyclization twice. All diastereomers of the spirodiketone could be stereoselectively prepared from the identical starting material by the combination of a neutral Rh(PPh3)3Cl and a cationic Rh[BINAP]ClO4. The cyclization by the neutral Rh(PPh3)3Cl proceeded to give cis-3,4-disubstituted cyclopentanones, while that by the cationic Rh[BINAP]ClO4 proceeded to afford trans-3,4-disubstituted cyclopentanones. Four spirodiketones of six stereoisomers could be prepared in optically active form, and the relationship between the stereochemistry of the spirodiketones and the Rh-complex was discussed based on the plausible acyl-hydride Rh-complexes.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::c9131e2f85b36ba6e413a5e617a3cfe6 https://doi.org/10.1016/s0040-4020(00)01106-6 Zobrazit plný text záznamu Full Text from ScienceDirect