Unusual behaviour of thermally generated oxygen 1,3-diradicals from β-peroxylactones: stereoselective synthesis of a tetrahydrofuran ring by intramolecular hydrogen abstraction
1990
Hernández, Rosendo | Marrero, José J. | Suárez, Ernesto | Dirección General de Investigación Científica y Técnica, DGICT (España) | Ministerio de Educación y Ciencia (España)
3 pages, 1 figure, 1 table, 1 scheme.
显示更多 [+] 显示较少 [-]Thermolysis of the steroidal β-peroxylactone (3) gave ether (4), produced by intramolecular hydrogen abstraction from a non-activated carbon; the reaction occurs with complete stereoselectivity by abstraction of the C7-pro-R hydrogen, and a concerted mechanism is proposed, no free radicals seem to be involved in the reaction since when a true free radical hydrogen abstraction was realized with alcohol (7) no selectivity was observed and a mixture of ethers (4) and (8) was obtained.
显示更多 [+] 显示较少 [-]This work was supported by the Investigation Programme No. PB0406 of the Dirección General de Investigación Científica y Técnica. J.J.M. thanks the Ministerio de Educación y Ciencia, Spain, for a fellowship.
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