Enantiospecific preparation of gem-dimethylcyclopropane fused cycloheptanes via valence tautomerization of 3,4-homotropilidene under thermodynamic and kinetic control
作者:Takashi Sugimura、Tohru Futagawa、Toshifumi Katagiri、Norio Nishiyama、Akira Tai
DOI:10.1016/0040-4039(96)01654-1
日期:1996.9
3,4-Homotropilidene derivatives were obtained as a stable compound by regioselectivedichlorocarbeneaddition to 4-alkoxy-8,8-dimethylcycloheptatrienes. Substitution of chlorine atomes to hydrogens in them by reduction with sodium affords rearranged products. By using stereospecificity of the rearrangement, the corresponding optically active products were also prepared.
Enantioselective Total Synthesis of (+)-Euphorikanin A
作者:Moritz J. Classen、Markus N. A. Böcker、Remo Roth、Willi M. Amberg、Erick M. Carreira
DOI:10.1021/jacs.1c04210
日期:2021.6.9
We disclose the first totalsynthesis of (+)-euphorikanin A, an ingenane-derived natural product featuring an unprecedented 5/6/7/3-fused tetracyclic skeleton. Key to the approach is a SmI2-mediated ketyl–enoate reaction that leads to the formation of two rings in a single step. The polarity-reversed cyclization proceeds in excellent yield and high diastereoselectivity. Access to ring B is effected
我们首次公开了 (+)-euphorikanin A 的全合成,这是一种源自 ingenane 的天然产物,具有前所未有的 5/6/7/3-稠合四环骨架。该方法的关键是 SmI 2介导的烯酮酸反应,该反应导致在一个步骤中形成两个环。极性反转的环化以优异的产率和高非对映选择性进行。通过实施许多化学选择性转化,包括原位生成乙烯基锂物质和随后对α-酮内酯的分子内攻击,在合成后期实现对环 B 的访问。
Bioinspired Total Synthesis of (+)‐Euphorikanin A
作者:Zhuang Chen、Kuan Zhao、Yanxing Jia
DOI:10.1002/anie.202200576
日期:2022.4.11
The bioinspiredtotalsynthesis of (+)-euphorikanin A, an intriguing and complex diterpenoid, was achieved by using an intramolecular nucleophile-catalyzed aldol lactonization of carboxylic acid–ketone to assemble the five-membered ring, a McMurry coupling to construct the seven-membered ring, and a biomimetic benzilic acid type rearrangement to form the bridged [3.2.1]-γ-lactone moiety.
Highly Practical and Enantioselective Cu-Catalyzed Conjugate Addition of Alkylzinc Reagents to Cyclic Enones at Ambient Temperature
作者:Isaac J. Krauss、James L. Leighton
DOI:10.1021/ol034983r
日期:2003.9.1
[GRAPHICS]A new ligand for Cu-catalyzed enantioselective additions of dialkylzincs to cyclic enones has been developed. In addition to providing good to excellent enantioselectivities with a range of cyclic enones and dialkylzincs, the ligand has several notworthy features: it can be readily prepared in just two steps, is an air-stable crystalline solid, and provides optimal performance at ambient temperature.
Satoh, Tsuyoshi; Kaneko, Youhei; Okuda, Teruyoshi, Chemical and pharmaceutical bulletin, 1984, vol. 32, # 9, p. 3452 - 3460
作者:Satoh, Tsuyoshi、Kaneko, Youhei、Okuda, Teruyoshi、Uwaya, Satoru、Yamakawa, Koji