Syntheses of (−)-gabosine A, (+)-4-epi-gabosine A, (−)-gabosine E, and (+)-4-epi-gabosine E
作者:Vikas Kumar、Pintu Das、Partha Ghosal、Arun K. Shaw
DOI:10.1016/j.tet.2011.04.082
日期:2011.6
1 and (−)-gabosine A 2 have been synthesized starting from methyl α,d-glucopyranoside and methyl α,d-mannopyranoside, respectively, by utilizing Pd(0) catalyzed Stille coupling as the key step. On the other hand, syntheses of (+)-4-epi-gabosine E 3 and (−)-gabosine E 4 have been accomplished from methyl α,d-glucopyranoside and from methyl α,d-mannopyranoside, respectively, by utilizing DMAP catalyzed
利用Pd(0)催化的Stille偶联反应分别从甲基α,d-吡喃葡萄糖苷和甲基α,d-甘露吡喃糖苷分别合成了(+)-4- Epi -Gabosine A 1和(-)-Gabosine A 2关键步骤。另一方面,已经由甲基α,d-吡喃葡萄糖苷和甲基α,d合成了(+)-4-表-葡萄糖苷E 3和(-)-葡萄糖苷E 4。-甘露吡喃糖苷分别通过利用DMAP催化的Morita-Baylis-Hillman反应作为关键步骤。糖衍生的环状烯酮的C-6位上存在乙酰基可防止MBH加合物的芳构化。还描述了一种合理的机制。