51505-46-5Relevant articles and documents
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
1,2-beta-methylene steroids
Wiechert,Engelfried,Kerb,Laurent,Müller,Schulz
, p. 1118 - 1127 (2007/10/10)
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