Synthesis of ovalicin starting from D-mannose.
[reaction: see text] A new synthesis of epoxyketone 22 is described that is a key intermediate in Barton's synthesis of ovalicin (2), a powerful anti-angiogenetic inhibitor. The key process for the construction of 22 was ring-closing metathesis of olefins 11 and 12 obtained from 2,3:5,6-di-O-isopropylidene-alpha-D-mannofuranose (4) and regioselective desilylation of tri-TES ether 19. Furthermore, an alternative stereoselective route from 22 into 2 has also been developed, and the overall yield of 2 from 4 was 10.0%.
Takahashi
Shunya
S
RIKEN (The Institute of Physical and Chemical Research), Wako-shi, Saitama, 351-0198, Japan. shunyat@riken.go.jp
Hishinuma
Nobuyuki
N
Koshino
Hiroyuki
H
Nakata
Tadashi
T
D008358:Mannose / Q000737:chemistry*; D008968:Molecular Conformation; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D012717:Sesquiterpenes; C002781:ovalicin; D008358:Mannose