A Flexible Strategy Based on a <i>C</i><sub>2</sub>-Symmetric Pool of Chiral Substrates: Concise Synthesis of (+)-Valienamine, Key Intermediate of (+)- Pancratistatin, and Conduramines A-1 and E
作者:Yuan-Kang Chang、Hong-Jay Lo、Tu-Hsin Yan
DOI:10.1021/ol9016194
日期:2009.10.1
A new strategy invoking a new application of the [3,3] sigmatropic rearrangement of allylic azides and the presence of a C2 symmetry element within a pool of chiral substrates was evolved. Not only does this simple flexible strategy provide a concise approach to (+)-valienamine, but it also can readily be adopted for the synthesis of conduramines A-1 and E and the enantiopure azido carbonate 4, a key
Preparation and conversion of chiral O-isopropylidene-protected 4-aminocyclohexenol to various key intermediates toward narcissus alkaloids
作者:Shanmugham Elango、Ying-Chuan Wang、Chien-Liang Cheng、Tu-Hsin Yan
DOI:10.1016/s0040-4039(02)00543-9
日期:2002.5
Enantiomerically pure 4-amino-5,6-O-isopropylidenedioxycyclohex-2-en-1-ol, conveniently prepared by the union of O-isopropylidenedioxycyclohexadiene with camphor-based chloronitroso ester, was employed in the synthesis of versatile key intermediates toward narcissus alkaloids. (C) 2002 Elsevier Science Ltd. All rights reserved.