151765-22-9Relevant academic research and scientific papers
Total Synthesis of Prostratin, a Bioactive Tigliane Diterpenoid: Access to Multi-Stereocenter Cyclohexanes from a Phenol
Ding, You-Song,Ding, Zhengwei,Li, Pengfei,Liu, Zhi,Tong, Guanghu,Xu, Liang,Zhang, Hailong
, p. 4813 - 4837 (2020/05/01)
Tiglianes such as prostratin and related diterpenoids are biologically significant natural molecules and long-standing targets for organic synthesis community. Due to the complex polycyclic scaffolds, high oxygenation level, and dense functional groups and stereocenters, their de novo chemical syntheses still face formidable challenges despite extensive efforts in the past 40 years. This account details the development of a modular and concise synthesis of prostratin, a potent anti-HIV and anticancer agent. The key approach in this synthesis involved a sequence of oxidative dearomatization and sequential stereoselective installation of peripheral groups to rapidly build the contiguously substituted cyclohexane C-ring. Inspired by Wender's work, an acid- A nd solvent-controlled stereodivergent formation of cyclopropane D-ring was developed. Mechanistic investigations by computational methods revealed that the competition between intra- A nd intermolecular hydrogen bonding led to different conformations, thus favoring different protonation processes. The designed and unexpected chemistry along this campaign reflected the uniqueness of the natural structures and should be amenable to future chemical syntheses of related complex polycyclic molecules.
Kinetic resolution of racemic 2-hydroxy-γ-butyrolactones by asymmetric esterification using diphenylacetic acid with pivalic anhydride and a chiral acyl-transfer catalyst
Nakata, Kenya,Gotoh, Kouya,Ono, Keisuke,Futami, Kengo,Shiina, Isamu
supporting information, p. 1170 - 1173 (2013/05/21)
Various optically active 2-hydroxy-γ-butyrolactone derivatives are produced via the kinetic resolution of racemic 2-hydroxy-γ-butyrolactones with diphenylacetic acid using pivalic anhydride and (R)-benzotetramisole ((R)-BTM), a chiral acyl-transfer catalyst. Importantly, the substrate scope of this novel protocol is fairly broad (12 examples, s-value; up to over 1000). In addition, we succeeded in disclosing the reaction mechanism to afford high enantioselectivity using theoretical calculations and expounded on the substituent effects at the C-3 positions in 2-hydroxylactones.
