Highly efficient epoxidation of unsaturated steroids using magnesium bis(monoperoxyphthalate) hexahydrate
作者:João F.S. Carvalho、M. Manuel Cruz Silva、M. Luisa Sá e Melo
DOI:10.1016/j.tet.2009.01.100
日期:2009.4
Fast generation of epoxides from the corresponding homoallylic and allylic steroidal olefins was developed by using magnesium bis(monoperoxyphthalate) hexahydrate (MMPP) as oxidant suspended in acetonitrile (CH3CN) at reflux temperature. The protocol involves the use of a safe readily available oxidant along with an easy work-up, which renders the process very efficient. Selective 4,5- and 5,6-epoxidations
Diastereoselective epoxidation of olefins by organo sulfonic peracids, II
作者:R. Kluge、M. Schulz、S. Liebsch
DOI:10.1016/0040-4020(95)01128-5
日期:1996.2
have investigated the behaviour of sulfonic peracids 2in situ generated towards olefins 7a,7b,9,11,14,16,18, allylic and homoallylic alcohols 20,22,24,26,28,30,33 and α,β-unsaturated ketones 35,37,39. Generally, the epoxidation proceeds in a peracid-like manner with greater diastereoselectivity than those by common oxidants. In particular, the epoxidation of Δ4 3-ketosteroids 39a-i led to 4α,5α-epoxides
Fourteen novelsteroidal C-17 pyrazolinyl derivatives 9a–g and 10a–g were synthesized from commercially available progesterone and tested for their cytotoxic activity against brine shrimp (Artemia salina) and three human cancer cell lines (NCI-H460, HeLa, and HepG2). Some of these synthetic compounds exhibited significant cytotoxic activity, and treatment of HeLa cells with compound 10b resulted in
Unambiguous assignment of 13C NMR signals in epimeric 4,5-epoxy-3-oxo-steroids assisted by X-ray diffraction and gauge invariant atomic orbitals calculation of absolute isotropic shieldings
作者:Pablo Labra-Vázquez、Annia Galano、Margarita Romero-Ávila、Marcos Flores-Álamo、Martín A. Iglesias-Arteaga
DOI:10.3998/ark.5550190.p008.237
日期:——
Complete assignments of the 13 C signals of diastereomeric 4,5-epoxy-3-oxosteroids based on a combination of 1D and 2D NMR techniques are described The assignments were corroborated or corrected by calculation of the absolute isotropic 13 C NMR shieldings using the Gauge Invariant
描述了基于 1D 和 2D NMR 技术组合的非对映体 4,5-epoxy-3-oxo 类固醇的 13 C 信号的完整分配 通过使用 Gauge 计算绝对各向同性 13 C NMR 屏蔽来证实或校正分配不变量