作者:Chang Yong Hong、Yoshito Kishi
DOI:10.1021/ja00044a008
日期:1992.8
An enantioselective total synthesis of (-)-decarbamoylsaxitoxin (2) has been accomplished, using the asymmetric trimolecular cyclization of 6, i.e., 6 + (R)-glyceraldehyde 2,3-acetonide + Si(NCS) 4 → α-7, as the key step. The structure of the major product α-7 was determined by X-ray crystallographic analysis, with the C-6 configuration corresponding to the unnatural antipode of decarbamoylsaxitoxin
已经完成了 (-)-decarbamoylsaxitoxin (2) 的对映选择性全合成,使用 6 的不对称三分子环化,即 6 + (R)-甘油醛 2,3-丙酮化物 + Si(NCS) 4 → α-7,作为关键步骤。主要产物 α-7 的结构由 X 射线晶体学分析确定,其 C-6 构型对应于 decarbamoylsaxitoxin 的非天然对映体。丙酮 α-7 被转化为硫脲 5,这是我们之前外消旋合成石房蛤毒素时使用的中间体。硫脲5进一步转化为三环脲-硫脲3