- Concise formal synthesis of (-)-7-deoxyloganin via N-heterocyclic carbene catalysed rearrangement of α,β-unsaturated enol esters
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NHC catalysed rearrangement of α,β-unsaturated enol esters derived from formyl acetates and cyclopentyl annulated α,β- unsaturated acids provides the cyclopentapyranone core of (-)-7-deoxyloganin (1) with diastereo- and chemoselectivity in 6 steps startin
- Candish, Lisa,Lupton, David W.
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p. 8182 - 8189
(2012/01/04)
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- The total synthesis of (-)-7-deoxyloganin via N-heterocyclic carbene catalyzed rearrangement of α,β-unsaturated enol esters
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The diastereoselective N-heterocyclic carbene (NHC) catalyzed rearrangement of α,β-unsaturated enol ester (S)-2b has been used to assemble dihydropyranone (S)-3b, a material embodying the bicyclic core of the iridoid family of natural products. Elaboration of this intermediate, by chemoselective reduction followed by stereoselective β-glycosylation, has allowed the total synthesis of (-)-7-deoxyloganin (1) to be achieved in four subsequent steps.
- Candish, Lisa,Lupton, David W.
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supporting information; experimental part
p. 4836 - 4839
(2011/02/23)
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- RADIOIMMUNOASSAY OF IRIDOID GLUCOSIDES: PART 1. GENERAL METHODS FOR PREPARATION OF THE HAPTENS AND THE CONJUGATES WITH A PROTEIN OF THIS SERIES OF GLUCOSIDES
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In order to obtain antibodies specific to three key intermediates, 7-deoxyloganin (1b), 7-deoxy-8-epi-loganin (2b) and 10-deoxygeniposide (3b), in biosynthesis of iridoid glucosides in behalf of their microdetermination by a radioimmunoassay technique in
- Inoue, Kenichiro,Ono, Masami,Nakajima, Hirotoshi,Fujie, Ikuko,Inouye, Hiroyuki,Fujita, Tetsuro
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p. 673 - 695
(2007/10/02)
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- SYNTHESIS OF IRIDOLACTONES ISOLATED FROM SILVER VINE
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The naturally occurring iridolactones, nepetalactone, isodihydronepetalactone, and iridomyrmecin are synthesized in optically active forms starting from natural glycoside geniposide.The stereogenic centers were introduced with highly stereoselective hydrogenations.
- Kigawa, Masaharu,Tanaka, Masahide,Mitsuhashi, Hiroshi,Wakamatsu, Takeshi
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p. 117 - 120
(2007/10/02)
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- BIOSYNTHESIS OF THE IRIDOID GLUCOSIDE CORNIN IN VERBENA OFFICINALIS
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The biosynthesis of cornin (verbenalin) and dihydrocornin in Verbena officinalis has been investigated.The incorporation of deoxyloganin was found to be largely independent of the incubation time between one day and a week.An improved method for the preparation of deoxygeniposide from gardenoside is reported and -iridodial glucoside and iridotrial glucoside were prepared from the former.Feeding experiments with young plants using these glucosides, as well as the aglucones, showed much better incorporations for the latter compounds as measured by 2H NMR spectroscopy. 13C-labelled 10-hydroxygeraniol, 10-hydroxycitronellol, iridodial, iridotrial, iridodial glucoside, iridotrial glucoside, deoxyloganic acid aglucone were prepared. -Mevalonic acid and the above compounds were fed to plants of medium age, and all gave incorporations measurable by 13C NMR spectroscopy into dihydrocornin.The postulated existence of two different metabolic pathways in the biosynthesis of cornin in young and old plants, respectively, could not be established as complete scrambling between the C-3 and C-11 in the iridoid skeleton apparently takes place with all the early precursors.The complete pathway from iridoidal forwards to hastatoside has been elucidated.Key Word Index- Verbena officinalis; Verbenaceae; cornin; dihydrocornin; iridoid glucosides; biosynthesis; 13C-labelling; 2H-labelling.
- Jensen, Soren Rosendal,Kirk, Ole,Nielsen, Bent Juhl
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- 7-DEOXYGARDOSIDE, A NEW ACID IRIDOID GLUCOSIDE FROM Argylia radiata
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From Argylia radiata (L.) D.Don a new acid iridoid glucoside has been isolated and its structure of 7-deoxygardoside assigned on the basis of spectroscopic data and reductive conversion into 7-deoxy-8-epiloganin.
- Bianco, Armandodoriano,Passacantilli, Pietro,Righi, Giuliana,Nicoletti, Marcello,Serafini, Mauro,et al.
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- Biosynthesis of the Iridoid Glucosides Cornin, Hastatoside, and Griselinoside in Verbena Species
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2H N.m.r. spectroscopy has been used to demonstrate that in specifically labelled deoxyloganin the label at C-8 is retained during its conversion into cornin in Verbena officinalis, thus excluding deoxygeniposide as an intermediate.Deoxygeniposide, loganin, and mussaenoside produced no measurable incorporation into cornin.In V. hastata deoxyloganin and dihydrocornin were incorporated into cornin and hastatoside while deoxygeniposide again gave no observable incorporation.Forsythide dimethyl ester was an efficient precursor for griselinoside in V. hispida, while no incorporation was observed with deoxygeniposide, geniposide, deoxyloganin, and dihydrocornin.However, the last two compounds were metabolized to cornin, otherwise absent in this species.Incorporation of forsythide dimethyl ester and geniposide into griselinoside in Griselinia littoralis was not observed.
- Damtoft, Soren,Jensen, Soren Rosendal,Nielsen, Bent Juhl
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p. 1943 - 1948
(2007/10/02)
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