Tetramethyldiamidophosphoric acid chloride mediated epoxide-diene conversion and steroidal aromatization

Date

2001-01-01

Author

Demir, Ayhan Sıtkı

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

78
views

0
downloads

The reaction of tetramethyldiamidophosphoric acid chloride with epoxides in the presence of a trace amount of water furnished 1,3-dienes in good yield. The conversion works with open chain and cyclic epoxides. A C-C bond cleavage reaction occurs if the epoxide contains a quaternary carbon. Application of this method to epoxy sterols afforded ring A aromatic steroids in good yield. The aromatization works via dienol-benzene rearrangements and is independent of the C-3 stereochemistry.

Subject Keywords

Epoxides, Dienes, Steroid and sterols, Aromatization

URI

https://hdl.handle.net/11511/57663

Journal

TETRAHEDRON

DOI

https://doi.org/10.1016/s0040-4020(00)01002-4

Collections

Department of Chemistry, Article

Suggestions

OpenMETU
Core

Dimethyl Ether Synthesis over Novel Silicotungstic Acid Incorporated Nanostructured Catalysts Ciftci, Aysegul; VARIŞLI, DİLEK; Doğu, Timur (2010-01-01) Dimethyl ether (DME), which is an excellent green diesel-fuel alternate with excellent clean burning properties, is synthesized by dehydration of methanol over novel solid acid catalysts, which are synthesized following a direct hydrothermal route and using silicotungstic acid (STA) as the active compound. These mesoporous silicate structured catalysts have surface area values of 108-393 m(2)/g, depending upon their W/Si ratio. These catalysts showed very high methanol dehydration activity and also very hig...
Conductimetric and potentiometric titration of some hydroxylated cinnamic acids with tetrabutylammonium hydroxide in non-aqueous media Aktas, AH; Yasar, G; Alsancak, O; Demirci, S (2001-01-01) In this study, four hydroxycinnamic acids, namely 3,4-dihydroxycinnamic acid, 4-hydroxycinnamic acid, 4-hydroxy -3- methoxycinnamic acid and 4-hydroxy-3,5-dimethoxycinnamic acid, were titrated conductimetrically and potentiometrically using triethylamine and tetrabutylammonium hydroxide in acetonitrile, 2-propanol, and pyridine solvents under a nitrogen atmosphere at 25 degreesC.
POLYMETHYLALUMINIUM OXIDE AND STEREOREGULAR POLYMERIZATION OF PROPYLENE-OXIDE OKTEM, Z; SARI, A; ALYURUK, K (Elsevier BV, 1993-05-01) Polymethylaluminium oxide (PMAO) was prepared by reacting trimethylaluminium (AlMe3) with water in dilute dioxane solution. Several PMAO samples with different degrees of polymerizations (DP) were prepared (1 less-than-or-equal-to DP less-than-or-equal-to 7) either by changing reaction conditions or by fractionating the products. PMAO with DP about unity was found to be trimeric in dilute dioxane solutions but, in higher dielectric solvents, it partially dissociated into free ions. Electrical conductance me...
Functionalization of oxabenzonorbornadiene: Manganese(III)-mediated oxidative addition of dimedone ÇALIŞKAN, Raşit; Sari, Ozlem; Balcı, Metin (Wiley, 2017-09-01) 3-Chloro-1,2,3,4-tetrahydro-1,4-epoxynaphthalen-2-yl)-3-hydroxy-5,5-dimethylcy-clohex- 2-en-1-one, synthesized by the reaction of oxabenzonorbornadiene with Mn(OAc)(3) and dimedone in the presence of HCl in acetic acid, was submitted to ring-opening reactions with BBr3 and H2SO4. Reaction with BBr3 yielded 2 products, a 5-membered ring and an 8-membered ring, with the former being the major product. However, the H2SO4-supported reaction exclusively formed an 8-membered ring. The mechanism of formation of th...
Activated carbon-tungstophosphoric acid catalysts for the synthesis of tert-amyl ethyl ether (TAEE) Obali, Zeynep; Doğu, Timur (2008-05-01) Catalytic activities of bulk tungstophosphoric acid (HPW) and its supported forms on activated carbon were investigated in the vapor phase etherification reaction of isoamylene with ethanol in a continuous flow reactor. Tungstophosphoric acid (H3PW12O40 center dot 11H(2)O) was supported on activated carbon having a surface area of 796 m(2)/g, at two different loading levels (25% and 31%) by aqueous impregnation technique and the kinetic experiments were done in a temperature range between 353 and 370 K. Sup...

Citation Formats

A. S. Demir, “Tetramethyldiamidophosphoric acid chloride mediated epoxide-diene conversion and steroidal aromatization,” TETRAHEDRON, pp. 227–233, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/57663.