Premium
Synthetic Studies on Camptothecins. Part 1
Author(s) -
Zhang LiPeng,
Bao Yong,
Kuang YunYan,
Chen FenEr
Publication year - 2008
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200890218
Subject(s) - chemistry , tricyclic , yield (engineering) , hydroxylation , camptothecin , lactone , pyridine , enantioselective synthesis , stereochemistry , total synthesis , organic chemistry , combinatorial chemistry , catalysis , enzyme , materials science , metallurgy
A six‐step asymmetric total synthesis of (20 S )‐camptothecin ( 1 ) has been accomplished in 25% overall yield starting from the known pyridone 3 . The key steps in this synthesis are the chemoselective Ni‐catalyzed hydrogenation of 3‐cyanopyridone 6 to 3‐formylpyridone 7 in AcOH/pyridine/H 2 O and the Davis asymmetric hydroxylation of tricyclic lactone 4 utilizing a chiral N ‐sulfonyloxaziridine into (4′ S )‐tricyclic hydroxylactone 2 .