- Determination of the stereochemistry of C-2' and C-3' positions of taxine NA-1 (2'-hydroxytaxine II) by the asymmetric synthesis of the reductive degradation product of its side chain moiety
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The reductive degradation of taxine NA-1 (2'-hydroxytaxine II) with n-Bu4NBH4 gave taxinine A and (-)-3-dimethylamino-3- phenylpropane-1,2-diol (1) in addition to 11,12-dihydrotaxinine A. The relative stereochemistry of (-)-1 was identical with syn-3-dimethylamino-3-phenylpropane- 1,2-diol, (±)-1b, which was synthesized from cis-2,3-epoxy-3- phenylpropan-1-ol, (±)-7. The absolute configuration of (-)-1 was certified by comparison of the specific optical rotation and the spectroscopic data of (-)-1 with those of (+)-1b and (-)-1b, which were enantioselectively synthesized by Sharpless asymmetric epoxidation reaction of cis-cinnamyl alcohol (6), respectively. As the result, the relative and absolute configuration of (-)-1 was same with that of (-)-1b possessing (2R, 3S) configuration. Thus, the absolute configuration of the side chain of taxine NA-1 (2'-hydroxytaxine II) at C-2' and C-3' positions was determined to be (2'R, 3'S).
- Tang, Wanxia,Minato, Hiroshi,Ando, Mariko,Ando, Masayoshi
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experimental part
p. 1697 - 1710
(2012/09/22)
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- Convenient methods for regio- and/or chemo-selective O-deacylation of taxinine, a naturally occurring taxane diterpenoid
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Selective O-deacylations of taxinine 1a, readily available from needles of Taxus cuspidata, at C-2, C-5 and C-9,10 have been accomplished by treatment with barium hydroxide octahydrate, sodium bis(2-methoxyethoxy)aluminium hydride (Red-Al) or diisobutylal
- Sako, Magoichi,Suzuki, Hikokazu,Yamamoto, Noriyuki,Hirota, Kosaku,Maki, Yoshifumi
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p. 417 - 421
(2007/10/03)
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