Efficient cleavage of cyclopropyl bond by adjacent ketyl radical generated under PET conditions
作者:Bipin Pandey、Ashok T. Rao、Pramod V. Dalvi、Pradeep Kumar
DOI:10.1016/s0040-4020(01)90404-1
日期:1994.3
Photolysis of various conjugated cyclopropyl and epoxy ketones in 20% triethyl amine (TEA) and ethanol leads to cleavage of cyclopropyl bond. Significant wavelength dependence phenomenon is observed during photolysis for the cleanliness and efficient photo transformation. Steroidal cyclopropyl ketones cleave efficiently at 300nm photolysis, whereas exo-cyclopropyl ketones cleave at 254nm. The regiochemistry
The synthesis of 2α,3α-isopropylidenedioxy-6,6-ethylenedioxy-5α-androst-15-en-17-one and its 2β,3β-isomer
作者:R. P. Litvinovskaya、A. V. Baranovsky、M. A. Averkova、V. A. Khripach
DOI:10.1134/s1068162007030089
日期:2007.5
Androstane and Delta(15)-androstane analogues of brassinosteroids were synthesized from dehydroepiandrosterone. The key stage, hydroxylation of 17 beta-acetoxyandrost-2-en-6-one double bond with OsO4, yielded the corresponding 2 alpha,3 alpha- and 2 beta,3 beta-diols. The target 2 alpha,3 alpha-isopropylidenedioxy-6,6-ethylenedioxy-5 alpha-androst-15-en-17-one and its 2 beta,3 beta-isomer were obtained by dehydrosilylation of the corresponding silylenol ethers with palladium acetate.