We describe the stereoselective transformation of diosgenin (4a) to (25R)-Î4-dafachronic acid (1a), (25R)-Î7-dafachronic acid (2a), and (25R)-cholestenoic acid (3a), which represent potential ligands for the hormonal receptor DAF-12 in Caenorhabditis elegans. Key-steps of our synthetic approach are a modified Clemmensen reduction of diosgenin (4a) and a double bond shift from the 5,6- to the 7,8-position. In the 25R-series, the Î7-dafachronic acid 2a exhibits the highest hormonal activity.
我们描述了二氢甾烯(4a)选择性转化为(25R)-Δ4-达法
喹酸(1a)、(25R)-Δ7-达法
喹酸(2a)和(25R)-
胆甾烷酸(3a)的过程,这些化合物代表了线虫(Caenorhabditis elegans)激素受体
DAF-12的潜在
配体。我们合成方法的关键步骤是对二氢甾烯(4a)的改进Clemmensen还原和双键从5,6位转移到7,8位。在25R系列中,Δ7-达法
喹酸2a显示出最高的激素活性。