13209-60-4Relevant articles and documents
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Ogata,Kawakami
, (1938)
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Novel stereoselective synthesis of 7β-methyl-substituted 5-androstene derivatives
Zheng, Yunhong,Li, Yuanchao
, p. 1603 - 1606 (2003)
The 7β-methyl-5-androstene derivatives 11a-c were prepared in good yield with high stereoselectivities starting from 3β-acetoxyandrost-5-en-17-one 4. The addition of methylmagnesium iodide to the 7-carbonyl group of 7a-c gave, after hydrolysis, two isomers 9a-c and 10a-c, which were stereoselectively deoxygenated by means of an ionic hydrogenation to afford the compounds 11a-c.
19-hydroxy steroids. V. 3 ,7 ,19-Trihydroxy-5-androsten-17-one 3,19-diacetate: a potential precursor in the biosynthesis of B-ring unsaturated estrogens.
Morand,Van Tongerloo
, p. 47 - 64 (1973)
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Cooperative Noncovalent Interactions Lead to a Highly Diastereoselective Sulfonyl-Directed Fluorination of Steroidal α,β-Unsaturated Hydrazones
Capilato, Joseph N.,Siegler, Maxime A.,Rowshanpour, Rozhin,Dudding, Travis,Lectka, Thomas
, p. 1300 - 1307 (2021/01/09)
A series of steroidal α,β-unsaturated hydrazones is presented whose behavior and reactivity are governed by various types of weak C-H hydrogen bonds. Several interesting features in a representative X-ray crystal structure and 1H NMR spectrum are examined that provide evidence for a unique bifurcated intramolecular C-H interaction. Moreover, these steroid derivatives undergo functionalization in the form of a highly regio- and stereoselective fluorination; the sulfonyl oxygen atoms are proposed to direct the fluorinating reagent through C-H hydrogen bonds.
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.
