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16-Ketene dithioacetal derivatives of 3β-hydroxy-13α-androst-5-en-17-one react with amidine, benzamidine, or guanidine to yield novel pyrimido-fused D-heteroannulated steroids. The reactions of 3β-hydroxy-16-hydroxymethylidene-13α-androst-5-en-17-one with N,N′-dinucleophiles furnish heterocycles containing a pyrazole ring fused to positions 16,17 of the sterane skeleton.  相似文献   
2.
Ionic liquids 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim](+)[PF(6)](-)) and 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim](+)[BF(4)](-)) were found to promote an unusual Wagner-Meerwein rearrangement of steroidal 16α,17α-epoxides leading to unnatural 13-epi-18-nor-16-one derivatives as the main products. These compounds were isolated in good to excellent yields. 16α-Hydroxy-Δ(13)-18-norsteroids, the results of the usual rearrangement, were obtained as minor components of the reaction mixtures. The ionic liquid [bmim](+)[PF(6)](-) was shown to induce C-ring aromatization of 16α,17α-epoxyestranes due to the formation of HF, the hydrolysis product of [PF(6)](-). Increasing amounts of HF and [PO(2)F(2)](-) were detected by (19)F and (31)P NMR when the ionic liquid was reused. The structures of the steroidal products, 16-oxo-18-nor-13α-steroid derivatives, 16α-hydroxy-Δ(13)-18-norsteroids, and C-aromatic compounds were determined by two-dimensional NMR techniques and high-resolution mass spectrometry (HRMS). The ionic liquids were recirculated efficiently.  相似文献   
3.
Summary. 3β-Hydroxy-16,17-seco-13α-androsta-5,16-dien-17-al was obtained from 3β-acetoxyandrost-5-en-17-one in six steps with a Grob fragmentation as the key step. This seco-steroid, containing a formyl group and an unsaturated side-chain in a sterically favourable cis position, is a useful synthon for the synthesis of novel heterocycles condensed to the 3β-hydroxy-13α-androst-5-en-17-one skeleton.  相似文献   
4.
Summary.  16-Ketene dithioacetal derivatives of 3β-hydroxy-13α-androst-5-en-17-one react with amidine, benzamidine, or guanidine to yield novel pyrimido-fused D-heteroannulated steroids. The reactions of 3β-hydroxy-16-hydroxymethylidene-13α-androst-5-en-17-one with N,N′-dinucleophiles furnish heterocycles containing a pyrazole ring fused to positions 16,17 of the sterane skeleton.  相似文献   
5.
3β-Hydroxy-16,17-seco-13α-androsta-5,16-dien-17-al was obtained from 3β-acetoxyandrost-5-en-17-one in six steps with a Grob fragmentation as the key step. This seco-steroid, containing a formyl group and an unsaturated side-chain in a sterically favourable cis position, is a useful synthon for the synthesis of novel heterocycles condensed to the 3β-hydroxy-13α-androst-5-en-17-one skeleton.  相似文献   
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