Synthetic Anthracyclinones, XXXI. Total Synthesis of Racemic εe-Rhodomycinonesvia Keto-Ester Cyclization
作者:Karsten Krohn、Wahyudi Priyono
DOI:10.1002/jlac.198619860902
日期:1986.9.12
The keto esters 15 – 17b were prepared by regioselective alkylation of the anthraquinone acetals 12 – 14 followed by cleavage of the acetals and methyl ethers and esterification. The tetracyclic trans-β-hydroxy esters 25 – 27b were formed predominantly upon treatment of 15 – 17b with Triton B in pyridine, whereas lithium amides in THF gave only the cis-hydroxy esters 28 and 29a. Stereoselective hydroxylation
酮酯15 - 17B是由蒽醌的位点选择性的烷基化制备的缩醛12 - 14通过的缩醛和甲基醚和酯化裂解其次。四环反式-β-羟基酯25 - 27B主要处理时的形成15 - 17B在吡啶用Triton B,而在THF氨基化锂,得到仅顺式-羟基酯28和29A。的立体选择性羟化25 - 27B得到rhodomycinones 38 -40A和6天然构型(顺式-2,4-二醇),而没有28 - 30B得到不是天然存在的反式-2,4-二醇41 - 43B。