2639-53-4Relevant articles and documents
Collisionally-induced dissociation mass spectra of organic sulfate anions
Attygalle,Garcia-Rubio,Ta,Meinwald
, p. 498 - 506 (2001)
The collisionally-induced dissociation mass spectra of a variety of organic sulfate ester anions are described and mechanistically rationalized. A cyclic syn-elimination pathway, analogous to that of the Cope elimination, is postulated for the commonly observed formation of bisulfate anion (HSO4-, m/z 97). Deuterium labeling experiments confirm that the proton transferred to oxygen during bisulfate elimination normally originates from the C-2 position, although examination of the spectra of polyfunctional steroids reveals that the proton abstracted may originate from more distant sites as well. Adamantyl, phenyl, and vinyl sulfate anions, which do not readily lend themselves to a cyclic syn-elimination, do not give rise to an m/z 97 ion. Instead, these sulfates undergo both heterolytic and homolytic S-O bond cleavages to yield an m/z M - 80 anion, resulting from loss of neutral SO3, as well as an ion at m/z 80, corresponding to SO3-·, respectively. Sulfates that can give rise to a resonance stabilized radical by homolytic C-O bond fission, as exemplified by benzyl and linalyl sulfates, can be recognized by the formation of an m/z 96 (SO4-·) ion.
Insights into the synthesis of steroidal A-ring olefins
Varela, Carla L.,Roleira, Fernanda M. F.,Costa, Saul C. P.,Pinto, Alexandra S. C. T.,Martins, Ana I. O. S.,Carvalho, Rui A.,Teixeira, Natercia A.,Correia-Da-Silva, Georgina,Tavares-Da-Silva, Elisiario
, p. 39 - 46 (2014/02/14)
The classical synthesis, followed by purification of the steroidal A-ring Δ1-olefin, 5α-androst-1-en-17-one (5), from the Δ1-3-keto enone, (5α,17β)-3-oxo-5-androst-1-en-17-yl acetate (1), through a strategy involving the reaction of Δ1- 3-hydroxy allylic alcohol, 3β-hydroxy-5α-androst-1-en-17β-yl acetate (2), with SOCl2, was revisited in order to prepare and biologically evaluate 5 as aromatase inhibitor for breast cancer treatment. Surprisingly, the followed strategy also afforded the isomeric Δ2-olefin 6 as a by-product, which could only be detected on the basis of NMR analysis. Optimization of the purification and detection procedures allowed us to reach 96% purity required for biological assays of compound 5. The same synthetic strategy was applied, using the Δ4-3-keto enone, 3-oxoandrost-4-en-17β-yl acetate (8), as starting material, to prepare the potent aromatase inhibitor Δ4-olefin, androst-4-en-17-one (15). Unexpectedly, a different aromatase inhibitor, the Δ3,5-diene, androst-3,5-dien-17-one (12), was formed. To overcome this drawback, another strategy was developed for the preparation of 15 from 8. The data now presented show the unequal reactivity of the two steroidal A-ring Δ1- and Δ4-3- hydroxy allylic alcohol intermediates, 3β-hydroxy-5α-androst-1-en- 17β-yl acetate (2) and 3β-hydroxyandrost-4-en-17β-yl acetate (9), towards SOCl2, and provides a new strategy for the preparation of the aromatase inhibitor 12. Additionally, a new pathway to prepare compound 15 was achieved, which avoids the formation of undesirable by-products. Copyright
2-(N-SUBSTITUTED PIPERAZINYL) STEROID DERIVATIVES
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Page/Page column 40; 70-71, (2010/06/17)
Novel chemical agents of Formula I are described herein. More specifically, 2-(N-substituted piperazinyl) pregnane and 2-(N-substituted piperazinyl) androstane derivatives exhibiting cytotoxicity on a variety of cancer cell lines are disclosed herein. (I)