Synthetic studies on the ambiguine family of alkaloids: construction of the ABCD ring system
摘要:
A racemic synthesis of the ABCD ring core of the ambiguines that preserves the tertiary alcohol has been accomplished in a convergent synthesis in 10 synthetic steps, in an overall yield of 46% from commercially available 4-bromoindole and m-methylanisole. (C) 2010 Elsevier Ltd. All rights reserved.
Access to Functionalized Quaternary Stereocenters via the Copper-Catalyzed Conjugate Addition of Monoorganozinc Bromide Reagents Enabled by <i>N</i>,<i>N-</i>Dimethylacetamide
作者:Tyler J. Fulton、Phebe L. Alley、Heather R. Rensch、Adriana M. Ackerman、Cameron B. Berlin、Michael R. Krout
DOI:10.1021/acs.joc.8b02201
日期:2018.12.7
reagents, readily obtained from alkyl bromides, display excellent reactivity with β,β-disubstituted enones and TMSCl in the presence of Cu(I) and Cu(II) salts to synthesize a variety of cyclic functionalized β-quaternary ketones in 38–99% yields and 9:1–20:1 diastereoselectivities. The conjugate addition features a pronounced improvement in DMA using monoorganozinc bromide reagents. A simple one-pot protocol
Triterpenoid total synthesis. Part 5. Synthetic disproof of the triterpene structure proposed for naurol A, a cytotoxic metabolite of a Pacific sponge
作者:Dai Nozawa、Hirosato Takikawa、Kenji Mori
DOI:10.1039/b002500n
日期:——
Naurol A is a cytotoxic metabolite isolated from a Pacific sponge, and 1 has been proposed as its structure. A mixture of (±)-1 and meso-1′ was synthesized from 4-tert-butyldimethylsilyloxy-3-methylcyclohex-2-en-1-one (6) employing the Stille coupling (10 + 11→1 + 1′) as the key step. Although the synthetic sample (1 + 1′) was a diastereomeric mixture at C-11, its spectral data (IR, UV, 1H and 13C
Total Synthesis of<i>N</i>-Methylwelwitindolinone D Isonitrile
作者:Vikram Bhat、Kevin M. Allan、Viresh H. Rawal
DOI:10.1021/ja201834u
日期:2011.4.20
Described is a concise totalsynthesis of N-methylwelwitindolinone Disonitrile, the first in a family of complex bicyclo[4.3.1]decane-containing indole alkaloids to yield to synthesis. The complete carbon core of the natural product was assembled rapidly through a Lewis acid-mediated alkylative coupling followed directly by a palladium-catalyzed enolate arylation reaction. The final ring of the pentacycle
描述了 N-methylwelwitindolinone D 异腈的简明全合成,这是一个复杂的含双环 [4.3.1] 癸烷的吲哚生物碱家族中第一个合成的。天然产物的完整碳核通过路易斯酸介导的烷基化偶联快速组装,然后直接进行钯催化的烯醇芳基化反应。五环的最后一个环通过吲哚氧化/环化引入,异腈通过醛重排为异硫氰酸酯然后脱硫安装。
A stereocontrolled approach towards highly oxygenated taxane C and CD-ring precursors
Based upon a remarkable beta-face diastereoselection. a stereocontrolled construction of bicyclic systems with the appropriate stereochemical disposition of the substituents belonging either to a Baccatin-1 C-ring precursor or a Taxol(R) CD-ring precursor is reported. (C) 2002 Elsevier Science Ltd. All rights reserved.