Total Synthesis of the Sesquiterpenoid Polyols (±)-Euonyminol and (±)-3,4-Dideoxymaytol, Core Constituents of Esters of the <i>Celastraceae</i>
作者:James D. White、Hyunik Shin、Tae-Seong Kim、Neil S. Cutshall
DOI:10.1021/ja963567h
日期:1997.3.1
exemplified with total syntheses of (±)-3,4-dideoxymaytol (3), the nucleus of ever-1 (6), and (±)-euonyminol (4), the sesquiterpenoid core of several cathedulins including K-19 (5). A focal intermediate 19, prepared by Diels−Alder addition of 11 to 12, was identified that permitted stereoselective introduction of an isopropenyl substituent via chelation-controlled, conjugate Grignard addition to give 34
Enantioselective synthesis and absolute configuration determination of hydroxywilfordic acid in sesquiterpene pyridine alkaloids
作者:Yue Yuan、Jong-Wha Jung、Seung-Yong Seo
DOI:10.1039/c8ob02364f
日期:——
An enantioselective synthetic route to hydroxywilfordic acid, a key subunit of sesquiterpene pyridine alkaloids such as wilfortrine, was developed. Asymmetric cyanation using Jacobsen's (R,R)-amino-thiourea and hydrolysis were performed to afford chiral α-hydroxy-α-methyl acid as the (S)-isomer. Naturally derived hydroxywilfordate prepared by methanolysis of wilfortrine was found to be the (R)-isomer
Development of an Enantioselective Synthesis of (−)-Euonyminol
作者:Martin Tomanik、Zhi Xu、Facheng Guo、Zechun Wang、Ke R. Yang、Victor S. Batista、Seth B. Herzon
DOI:10.1021/acs.joc.1c02167
日期:2021.12.3
first-generation approach. Computational studies suggest that the mechanism of this transformation proceeds via a direct 6-endo-trig cyclization, although a competing 5-exo-trig cyclization, followed by a rearrangement, is also energetically viable. We also detail the challenges associated with manipulating the oxidation state of late-stage intermediates, which may inform efforts to access other derivatives such
strategy for enantioselective totalsynthesis of 1 and 2. Starting from (R)-glycerol acetonide, we constructed the B-ring by an Et3N-accelerated Diels–Alder reaction, the C-ring by intramolecular iodoetherification, and the A-ring by ring-closing olefin metathesis. The 10 stereocenters were installed through a series of substrate-controlled stereoselective C–C and C–O bond formations by exploiting the three-dimensional