作者:N. Ya. Grigorieva、V. A. Popovsky、A. V. Stepanov、E. D. Lubuzh
DOI:10.1007/s11172-010-0359-x
日期:2010.11
Known synthetic precursors of strobilurins A and X, i.e., methyl (3Z,5E)-6-aryl-3-methylhexa-3,5-dienoates (aryl is phenyl, 4-methoxyphenyl), were synthesized by highly stereospecific reactions from 2-(2-tert-butyldimethylsilyloxyethyl)- and 2-[2-(4-methoxybenzyloxy)-ethyl]-5-arylpenta-2E,4E-dien-1-ols. These dienols were efficiently dehydroxylated to (1E,3Z)-4-methyl-6-(4-methoxybenzyloxy)hexa-1,3-dienylarenes with their subsequent demethoxyben-zylation to (3Z,5E)-6-aryl-3-methylhexa-3,5-dien-1-ols. The latter through the step of corresponding aryldienals and aryldienoic acids were transformed to the target methyl (3Z,5E)-6-aryl-3-methylhexa-3,5-dienoates, which completes a formal synthesis of strobilurins A and X. Configuration of the C=C bonds of the conjugated aryldiene system is preserved in the considered transformations by 95–97%.
通过高度立体特异性反应,从 2-(2-叔丁基二甲基硅氧基乙基)-和 2-[2-(4-甲氧基苄氧基)-乙基]-5-芳基戊-2E,4E-二烯-1-醇合成了已知的石杉碱甲和石杉碱 X 的合成前体,即 (3Z,5E)-6-芳基-3-甲基己-3,5-二烯酸甲酯(芳基是苯基,4-甲氧基苯基)。这些二烯醇被有效地脱羟基为(1E,3Z)-4-甲基-6-(4-甲氧基苄氧基)己-1,3-二烯-1-醇,并随后被脱甲氧基苄基化为(3Z,5E)-6-芳基-3-甲基己-3,5-二烯-1-醇。后者通过相应的芳基二烯烃和芳基二烯酸步骤转化为目标甲基 (3Z,5E)-6-芳基-3-甲基六-3,5-二烯酸酯,从而完成了石杉碱甲和石杉碱十的正式合成。在所考虑的转化过程中,共轭芳基二烯烃体系的 C=C 键的构型保留了 95-97%。