Synthesis of robustol trimethyl ether

1973 ◽  
Vol 26 (10) ◽  
pp. 2277 ◽  
Author(s):  
JR Cannon ◽  
BW Metcalf
Keyword(s):  
Model Compounds ◽  
New Synthesis ◽  
Trimethyl Ether

The macrocyclic substance robustol trimethyl ether (2) has been synthesized by an unambiguous method. ��� During a study of the reactions of model compounds a new synthesis of 1,14-bis-(3?,5?-dimethoxyphenyl)tetradecane (4) has been developed.

scholarly journals A New Synthesis of Model Compounds for the beta-5 Structural Unit in Lignins.

1984 ◽  
Vol 38b ◽  
pp. 335-336 ◽  
Author(s):  
Gösta Brunow ◽  
Knut Lundquist ◽  
Kjell Carlström ◽  
Holger Sköldefors ◽  
Nils Wilking ◽  
...  
Keyword(s):  
Structural Unit ◽  
Model Compounds ◽  
New Synthesis

Flavonoid intermediates for the synthesis of mopanol trimethyl ether[trans-trans-7,7',8'-Trimethoxyisochromano(4',3':2,3)chroman-4-ol]

1976 ◽  
Vol 29 (1) ◽  
pp. 191 ◽  
Author(s):  
JW Clark-Lewis ◽  
DP Cox
Keyword(s):  
Carboxylic Acid ◽  
Potassium Carbonate ◽  
Dimethyl Sulphate ◽  
Metal Hydrides ◽  
Cyclic Ether ◽  
Protecting Group ◽  
Model Compounds ◽  
Initial Product ◽  
Dibenzyl Ether ◽  
Trimethyl Ether

Preparation of a number of intermediates for the synthesis of (�)-mopanol trimethyl ether is described, together with exploratory reactions with model compounds, and especially with 7-methoxyflavanone-2'-carboxylic acid. 7-Methoxyflavan-4-ol, the initial product from reduction of 7-methoxyflavanone-2'-carboxylic acid with complex metal hydrides, was found to undergo facile dehydration to a novel intramolecular dibenzyl ether [the cyclic ether (19)*]. It was noted that the methoxymethyl group, which may be used as a protecting group for phenols, did not survive the conditions of methylation with dimethyl sulphate and potassium carbonate in acetone.

Flavan derivatives. XVIII. Synthesis of hemiketals containing the peltogynol ring system: 3(3')-Hydroxyisochromano (4',3':2, 3) chromans. Conversion of 2'-hydroxychdcones into flav-3-enes and its biosyntheticimplications

1967 ◽  
Vol 20 (10) ◽  
pp. 2169
Author(s):  
JW Clark-Lewis ◽  
DC Skingle
Keyword(s):  
Biosynthetic Pathway ◽  
Ring System ◽  
Mechanism Of Formation ◽  
Biological Reduction ◽  
Mass Spectral ◽  
Lithium Aluminium ◽  
Cis And Trans Isomers ◽  
New Synthesis ◽  
Trimethyl Ether ◽  
Cis And Trans

Reduction of three 1?-oxoisochromeno(4?,3?:2,3)chromones [chromeno(3?,2?: 3,4)isocoumarins] with lithium aluminium hydride has been shown to yield 3(3?)-hydroxyisochromano(4?,3?:2,3)chromans (hemiketals). The structures of these compounds (the 7-methoxy, 7,6?,7?-trimethoxy, and parent hemiketals) were unequivocally established by N.M.R., mass spectral, and chemical data. The hemiketals contain the peltogynol ring system, and one of them is the 7,6?,7?- trimethyl ether of the structure originally proposed for this leucoanthocyanidin by Robinson and Robinson. The hemiketals were obtained as mixtures of cis- and trans- isomers which underwent equilibration in deuterochloroform or in wet chloroform, and configurations were assigned to the isomers from a detailed study of their N.M.R. spectra. The hemiketals suffered dehydration when heated further in deuterochloroform, and gave the isochromeno(4?,3?:2,3)chromens (flav-2-enes), which immediately gave the flavylium salts with cold acids in air. The flavylium salts were also formed very readily from the hemiketals and acid, and the trimethoxy- henliketal gave the peltogynidin trimethyl ether cation. In connection with the mechanism of formation of the hemiketals from chromenoisocoumarins it was found that 2?-hydroxychalcones are reduced by sodium borohydride to flav-3-enes, and these readily give anthocyanidins when treated with acid. Parallel biological reduction of chalcones is clearly possible and a plausible, new, biosynthetic pathway leading directly from 2?-hydroxychalcones to anthocyanidins and catechins is proposed. Flav-3-enes are valuable intermediates for preparation of flavans, flavan derivatives, and flavylium salts, and the new synthesis makes flav-3-enes readily accessible in one stage from 2?-hydroxychalcones.

Tandem Carbon-Radical Peroxidation−Addition to Carbonyl Groups Reaction. A New Synthesis of Steroidal β-Peroxy Lactones

1996 ◽  
Vol 61 (26) ◽  
pp. 9635-9635
Author(s):  
Alicia Boto ◽  
Rosendo Hernández ◽  
Ernesto Suárez ◽  
Carmen Betancor ◽  
María S. Rodríguez
Keyword(s):  
Carbonyl Groups ◽  
New Synthesis

1,3-Selenaphospholes: A New Synthesis from 1,2,3-Selenadiazoles and Kinetically Stabilized Phosphaalkynes1

Synlett ◽  
1991 ◽  
Vol 1991 (04) ◽  
pp. 356-358 ◽  
Author(s):  
Bernd Burkhart ◽  
Steffen Krill ◽  
Yoshinori Okano ◽  
Wataru Ando ◽  
Manfred Regitz
Keyword(s):  
New Synthesis

A New Synthesis and Analysis of Silica Nanowire Periodically Wrapped by Nano-spheres

2016 ◽  
Vol 31 (5) ◽  
pp. 523
Author(s):  
MA Hong-Bing ◽  
BAI Hua ◽  
XUE Chen ◽  
TAO Peng-Fei ◽  
XU Qun-Feng ◽  
...  
Keyword(s):  
New Synthesis

Structure Revision of Protoaculeine B, a Posttranslationally Modified N-Terminal Residue in the Peptide Toxin Aculeine B

2020 ◽  
Author(s):  
Raku Irie ◽  
Kei Miyako ◽  
Satoko Matsunaga ◽  
Ryuichi Sakai ◽  
Masato Oikawa
Keyword(s):  
Mass Spectra ◽  
Chemical Reactivity ◽  
Model Compounds ◽  
Structural Revision ◽  
Structure Revision ◽  
Peptide Toxin ◽  
One Step ◽  
Marine Peptide ◽  
Synthetic Models ◽  
Long Chain

<div>Here, we newly propose the structure of protoaculeine B, an N-terminal moiety of the marine peptide toxin aculeine B, as possessing the cis-disubstituted tetrahydro-beta-carboline framework. We prepared two truncated model compounds that lack long-chain polyamine by one-step Pictet-Spengler reaction of tryptophan, and compared the NMR and mass spectra and chemical reactivity with those of natural protoaculeine B. The synthetic models reproduced the profiles of the natural product well, which was conclusive for the structural revision.</div>

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