119720-01-3Relevant academic research and scientific papers
Synthesis and antimicrobial activity of novel oxysterols from lanosterol
Shingate, Bapurao B.,Hazra, Braja G.,Salunke, Deepak B.,Pore, Vandana S.,Shirazi, Fazal,Deshpande, Mukund V.
, p. 11155 - 11163 (2013)
Chemically diverse oxysterols and their synthetic manipulations were carried out from variety of Δ8(9)-lanosterol derivatives and evaluated for their in vitro antimicrobial activities. Most of the synthesized oxysterols exhibited significant antifungal activity against the tested strains.
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.
body text, 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.
LANOSTANE TO CUCURBITANE TRANSFORMATIONS
Edwards, O. E.,Kolt, R. J.
, p. 595 - 612 (2007/10/02)
Transformation of 3,7,9,11-tetraoxygenated lanostane derivatives into 3,7,11-trioxygenated cucurbit-1(10)-enes and cucurbit-5(10)-enes has been achieved.Attempts to convert the latter in good yield into cucurbit-5-enes are documented.The steric and electronic factors influencing the course of dehydration, under Westphalen conditions, of 9α-hydroxylanostane derivatives are discussed.Unusual autooxidation and dehydrogenation promoted by rhodium trichloride and iron pentacarbonyl are described.
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.
TETRACYCLIC TRITERPENES. PART IX. A NEW CONVERSION OF LANOSTEROL TO LANOST-9(11)-EN-7-ONE
Wydra, Roman,Paryzek, Zdzislaw
, p. 705 - 710 (2007/10/02)
The synthesis of 5α-lanost-9(11)-ene-3,7-dione from 3β-acetoxy-5α-lanostane-7,11-dione has been described.An unusual oxidation of 3β,7-diacetoxy-5α-lanosta-7,9(11)-diene in the course of the reaction of this compound with lithium aluminium hydride in diethyl ether is also reported.
PHOTOCHEMICAL REARRANGEMENTS OF 18-HYDROXYLATED LANOSTEROL DERIVATIVES
Habermehl, Gerhard G.,Kirsch, Juergen H.,Reibstein, Karl J.
, p. 183 - 189 (2007/10/02)
Several lanosterol derivatives with 18-hydroxyl group were subjected to the hypoiodite reaction.A new C-secosteroid was obtained as well as the desired 5-membered 18,20-epoxy compound.
