State Key Laboratory of Natural Medicines, Department of Natural Medicinal Chemistry, China Pharmaceutical University , 24 Tong Jia Xiang, Nanjing 210009, People's Republic of China.
Org Lett. 2016 Apr 15;18(8):1924-7. doi: 10.1021/acs.orglett.6b00738. Epub 2016 Apr 7.
Spirotrichilins A (1) and B (2), two novel limonoids with an unprecedented spiro[cyclopenta[b]furan-2,1'-cyclopentan] ring system in A/B/C rings, were isolated from the fruits of trichilia connaroides. Their planar structures and absolute configurations were established based on 1D-, 2D-NMR data, electronic circular dichroism (ECD) exciton chirality method and time-dependent density functional theory (TDDFT)/ECD calculation. A benzilic acid-like rearrangement in ring A was proposed as the key step in the plausible biogenetic pathway of 1 and 2.
螺环三萜烯 A（1）和 B（2）是从川滇木莲果实中分离得到的两种新型倍半萜，其在 A/B/C 环中具有前所未有的螺[环戊[b]呋喃-2,1'-环戊烷]环系统。基于 1D-NMR、2D-NMR 数据、电子圆二色性（ECD）外消旋手性法和时间相关密度泛函理论（TDDFT）/ECD 计算，确定了它们的平面结构和绝对构型。提出了 A 环中的苯并乙酸样重排是 1 和 2 的可能生物合成途径中的关键步骤。
