2115-49-3Relevant articles and documents
Multiple Enone-Directed Reactivity Modes Lead to the Selective Photochemical Fluorination of Polycyclic Terpenoid Derivatives
Pitts, Cody Ross,Bume, Desta Doro,Harry, Stefan Andrew,Siegler, Maxime A.,Lectka, Thomas
supporting information, p. 2208 - 2211 (2017/02/23)
In the realm of aliphatic fluorination, the problem of reactivity has been very successfully addressed in recent years. In contrast, the associated problem of selectivity, that is, directing fluorination to specific sites in complex molecules, remains a great, fundamental challenge. In this report, we show that the enone functional group, upon photoexcitation, provides a solution. Based solely on orientation of the oxygen atom, site-selective photochemical fluorination is achieved on steroids and bioactive polycycles with up to 65 different sp3 C-H bonds. We have also found that γ-, β-, homoallylic, and allylic fluorination are all possible and predictable through the theoretical modes reported herein. Lastly, we present a preliminary mechanistic hypothesis characterized by intramolecular hydrogen atom transfer, radical fluorination, and ultimate restoration of the enone. In all, these results provide a leap forward in the design of selective fluorination of complex substrates that should be relevant to drug discovery, where fluorine plays a prominent role.
RuCl3-TBHP mediated allylic oxidation of Δ8(9) lanosterol derivatives
Shingate, Bapurao B.,Hazra, Braja G.,Salunke, Deepak B.,Pore, Vandana S.
supporting information; experimental part, p. 6007 - 6010 (2011/11/30)
A variety of Δ8(9)-lanosterol derivatives were converted into 7,11-dienones using t-butyl hydroperoxide in the presence of ruthenium chloride (RuCl3) in good yields.
Tetracyclic triterpenes. VIII. The skeletal rearrangement of 3β-acetoxy-9α,11α-epoxy-5α-lanostan-7-one: 13- and 10-methyl group migration
Paryzek, Zdzislaw,Widra, Roman
, p. 1280 - 1286 (2007/10/02)
The boron trifluoride etherate catalyzed rearrangement of 3β-acetoxy-9α, 11α-epoxy-5α-lanostan-7-one (1) in acetic acid anhydride resulted in formation of 19(10->9β)abeo compounds 2 and 4 along with 18(13->12β)abeo compound 5, as the major product.These structures are supported by spectral data and chemical transfomations.The possible mechanism of the rearrangements is discussed.
