Perfluoroalkylsulfonyl fluoride in organic synthesis: a facile synthesis of 17α-hydroxy steroids
作者:Peng-Peng Guo、Kai Ding
DOI:10.1016/j.tetlet.2015.05.026
日期:2015.7
A facile synthesis of 17α-hydroxysteroids with perfluoroalkylsulfonyl fluoride as hydroxyl activating agent was reported. The method features mild (40 °C), rapid (0.5 h), high yield, and high functional group tolerance. Notably, the method is applicable to HCOOH and CF3COOH, unusual and synthetically useful nucleophiles in hydroxyl inversion reaction.
Recyclable Dirhodium(II) Catalyst Rh<sub>2</sub>(esp)<sub>2</sub> for the Allylic Oxidation of Δ<sup>5</sup>-Steroids
作者:Yi Wang、Yi Kuang、Hongyang Zhang、Ruocheng Ma、Yuanhua Wang
DOI:10.1021/acs.joc.7b00414
日期:2017.5.5
The Rh2(esp)2 complex did not undergo catalytic degradation and was recycled using Merrifield–pyridine resin for further allylicoxidation cycles. The results of ultraviolet/visible spectral analysis suggested that the Rh2(II,II) species, rather than the Rh2(II,III) species, was in the catalyst resting state during the reaction, which helps to explain the high durability of the catalyst.
The long-range effect of substituents in the 17-position on the hydrogenation of double bond of the steroidal ∆4-3-ketones in acetic acid on a platinum catalyst is described in a series of testosterone (1) and epitestosterone (5) esters with carboxylic acids of varying alkyl chain length. The ratio 5α- to 5β-products is affected by the nature of substituents in the position 17.