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A comparative study of remote oxy-functionalization of unactivated carbons in 5β-steroids by dimethyldioxirane and 2,6-dichloropyridine N-oxide / ruthenium-porphyrin / HBr
| Content Provider | Semantic Scholar |
|---|---|
| Author | Iida, Takashi Ogawa, Shoujiro Shiraishi, Keisuke Kakiyama, Genta Goto, Takaaki Mano, Nariyasu Goto, Junichi |
| Copyright Year | 2003 |
| Abstract | Remote oxy-functionalization of methyl 3α-acetoxyand 3-oxo-5β-cholan-24-oates with 2,6dichloropyridine (DCP) N-oxide catalyzed by (5,10,15,20-tetramesitylporphyrinate) ruthenium (II) carbonyl complex [Ru(TMP)CO] and HBr was compared with that with dimethyldioxirane (DMDO). Treatment of the 5β-steroids with DMDO afforded the corresponding 5βand 17αmonohydroxylated and 5β,14αand 5β,17α-dihydroxylated compounds. On the other hand, the corresponding 20S-monoand 5β,20S-dioxygenated derivatives (as the γ-lactones), along with 5β-hydroxy compounds, were found to be the major oxidation products of the 5β-steroids with the DCP N-oxide / Ru(TMP)CO / HBr system. Both the reagents oxidized unactivated methine carbons stereoselectively, but the degree of regioselectivity depended upon the oxidants employed and the structure of the hydroxyl-protecting groups at C-3 (acetoxyl or carbonyl) of the substrates. |
| File Format | PDF HTM / HTML |
| DOI | 10.3998/ark.5550190.0004.817 |
| Volume Number | 2003 |
| Alternate Webpage(s) | https://www.arkat-usa.org/get-file/19952/ |
| Alternate Webpage(s) | https://doi.org/10.3998/ark.5550190.0004.817 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
