The osmium-catalyzed asymmetric dihydroxylation of cis-fused cyclopenteno-1,2,4-trioxanes
| Autor: | Géza Timári, Allan P. Dishington, Gérald Bernardinelli, Dharmendra Misra, Jean-Claude Rossier, Charles W. Jefford |
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| Rok vydání: | 1994 |
| Předmět: |
Double diastereoselectivity
Organic peroxide Chemistry Organic Chemistry Enantioselective synthesis chemistry.chemical_element Biochemistry Kinetic resolution Catalysis chemistry.chemical_compound Dihydroxylation 1.2-Diol Yield (chemistry) Reagent ddc:540 Drug Discovery X-Ray Dicamphanates Organic chemistry Osmium |
| Zdroj: | Tetrahedron Letters, Vol. 35, No 34 (1994) pp. 6275-6278 |
| ISSN: | 0040-4039 |
| DOI: | 10.1016/s0040-4039(00)73410-1 |
| Popis: | Submission of racemic, cis-fused cyclopenteno-1,2,4-trioxanes (1 and 1-ent) to catalytic amounts of K₂OsO₄ and (DHQD)₂PHAL and 1.2 equivalents of N-methylmorpholine N-oxide in aqueous acetone at 20°C (hybrid AD-mix-β) for 2 h gave the (-)-enantiomer, 1-ent (ee 95%) in 30% yield. The same reaction, but with (DHQ)₂PHAL, (hybrid AD-mix-α) afforded the (+)-enantiomer, 1 (ee 95%) in 25% yield after 2.7 h reaction. Similar, efficient kinetic resolution of the racemic di-p-fluoro analogues (2 and 2-ent) was also achieved with the same reagents. |
| Databáze: | OpenAIRE |
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