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出 处:《合成化学》2008年第4期483-486,共4页Chinese Journal of Synthetic Chemistry
摘 要:麦角甾烷-5,7(E),10(19),22(E)-四烯-6(S)-二氧化硫(1)经臭氧化反应合成了钙伯三醇(MC903)的重要中间体——麦角甾烷-5,7(E),10(19)-三烯-6(S)-二氧化硫(2),其结构经1H NMR和13C NMR表征。较佳的臭氧化反应条件为:11.0mmol,溶剂为V(二氯甲烷)∶V(甲醇)=4∶1,于-65℃^-78℃反应12min。在此条件下,2中醛基α-位的差相异构化降至最低程度,产率90%。对差相异构化的机理进行了讨论。The Key Imtermediate of MC903 ergosta-5,7(E) ,10(19)-triene-6(S)-sulfur dioxide (2) was synthesized from ergosta-5,7 (E), 10 ( 19 ) ,22(E) -tetraterpene-(6S) -sulfur dioxide ( 1 ) by ozonization. The structure was characterized by 1H NMR and ^13C NMR. The optimal ozonization conditions at -65 ℃ -78 ℃ for 12 min were as follows: 1 was 1.0 mmol; solvent V(CH2Cl2) :V (MeOH) was 4 : 1. The degree of epimerization in the a-position of aldehyde group was minimized under the optimal conditions and the yield was 90.0%. The mechanism of epimerization was also discussed.
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