85197-77-9Relevant academic research and scientific papers
Selective thioketalization process, process for preparing thioenol ethers from thioketals, and process for the preparation of thioketals
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, (2008/06/13)
A selective thioketalization process for the preparation of a thioketal from a dione where one, but not the other, keto group of the dione is α,β-unsaturated, and where selective thioketalization occurs at the keto group of the dione which is not α,β-unsaturated, comprising the step of contacting the dione with a thiol, in the presence of a protic acid catalyst which is a complex of a Lewis acid and a protic source, wherein the temperature of the reaction medium is maintained below about 25°C during the reaction. Preferably, further, (i) the acid catalyst is employed in excess and/or (ii) the thiol is employed in excess. The inventive process may be employed, for example, in the preparation of a 3-keto,17-thioketalandrostene from the corresponding 3,17-diketoandrostene. A process for the preparation of thioenolethers from thioketals, especially 3-keto,17-thioenoletherandrostenes from 3-keto,17-thioketalandrostenes, wherein the thioketal is contacted with a protic acid catalyst. A process for the preparation of thioketals, especially mixed thioketals such as mixed 3-keto,17-thioketalandrostenes, from thioenolethers, comprising the step of contacting a thioenolether with a thiol in the presence of a protic acid catalyst.
Antiinflammatory 17,17-bis (substituted thio) androstenes
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, (2008/06/13)
3-Ketoandrostenes having in the 17-position the substituents R1 --S-- and R2 --S-- wherein R1 and R2 are the same or different and each is alkyl, cycloalkyl or aryl, have antiinflammatory activity.
