Enantiodivergent Synthesis of Either Enantiomer of ABCDE-Ring Analogue of Antitumor Antibiotic Fredericamycin A via Intramolecular [4 + 2] Cycloaddition Approach
作者:Shuji Akai、Toshiaki Tsujino、Nobuhisa Fukuda、Kiyosei Iio、Yoshifumi Takeda、Ken-ichi Kawaguchi、Tadaatsu Naka、Kazuhiro Higuchi、Yasuyuki Kita
DOI:10.1021/ol016696y
日期:2001.12.1
[reaction: see text] An intramolecular enantiodivergent synthesis of both enantiomers of the ABCDE-ring analogue 22 of fredericamycin A is reported. Key steps involve an intramolecular [4 + 2] cycloaddition of 17 and an aromaticPummerer-typereaction of 19. A lipase-catalyzed enantioselective desymmetrization of prochiral diol 2 using 1-ethoxyvinyl 2-furoate 3 led to the pivotal intermediate (R)-4