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。
Regioselective Synthesis of Chirally Enriched Tetrahydrocarbazolones and Tetrahydrocarbazoles
作者:Chintam Narayana、Priti Kumari、Ram Sagar
DOI:10.1021/acs.orglett.8b01656
日期:2018.7.20
A new one-step, reagent-directed regioselectivesynthesis of chirally enriched tetrahydrocarbazolones and tetrahydrocarbazoles from a common type of substrate has been developed. The salient features of this method include inherited stereodiversity, a broad substrate scope, a quick reaction time, and a benign catalyst. The method is applicable to the synthesis of a bioactive cryptosanguinolentine precursor
Chiron approach to the total synthesis of Amaryllidaceae alkaloid (+)-lycoricidine
作者:Puli Saidhareddy、Arun K. Shaw
DOI:10.1016/j.tet.2017.10.033
日期:2017.11
A highly stereoselective totalsynthesis of Amaryllidaceae alkaloid starting from α-d-galactopyranoside has been described. The salient features of this totalsynthesis are Ferrier carbocyclization reaction for the synthesis of ring A and Suzuki Miyaura coupling of chiral α-iodo enone fragment with aromatic boronic acid followed by modified Bischler-Napieralski cyclization reaction to form the lactam