- ROTENOIDS FROM ROOTS OF MILLETTIA PACHYCARPA
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Roots of Millettia pachycarpa furnished rotenone, cis-12a-hydroxyrotenone, rot-2'-enonic acid and cis-12a-hydroxyrot-2'-enonic aicd.Key Word Index - Millettia pachycarpa; Leguminosae; Lototoidae; rotenone; cis-12a-hydroxyrotenone; rot-2'-enonic acid; cis-12a-hydroxyrot-2'-enonic acid.
- Singhal, Ashok Kumar,Sharma, Ram Prakash,Baruah, Jogendra Nath,Govindan, Serengolam V.,Herz, Werner
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- General Synthetic Approach to Rotenoids via Stereospecific, Group-Selective 1,2-Rearrangement and Dual S N Ar Cyclizations of Aryl Fluorides
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A general synthetic approach to rotenoids is described, featuring 1) stereospecific, group-selective 1,2-rearrangements of epoxy alcohols, and 2) S N Ar oxy-cyclizations of aryl fluorides. The common intermediate epoxyketone, en route to (-)-rotenone and (-)-deguelin, was prepared from d -araboascorbic acid in five steps. Also described is the conversion of (-)-deguelin into oxidized congeners, (-)-tephrosin and (+)-12a- epi -tephrosin.
- Matsuoka, Seiya,Nakamura, Kayo,Ohmori, Ken,Suzuki, Keisuke
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p. 1139 - 1156
(2019/02/26)
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- Stereocontrolled Total Syntheses of (?)-Rotenone and (?)-Dalpanol by 1,2-Rearrangement and SNAr Oxycyclizations
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The total syntheses of (?)-rotenone and (?)-dalpanol have been achieved by a group-selective, stereospecific 1,2-shift of an epoxy alcohol and SNAr cyclizations. Three oxacycles are constructed, thus illustrating a versatile synthetic route to various rotenoids.
- Nakamura, Kayo,Ohmori, Ken,Suzuki, Keisuke
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p. 182 - 187
(2016/12/30)
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- The first stereoselective synthesis of the natural product, rotenone
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The total syntheses of rotenone and munduserone are reported in this paper. The synthesis of rotenone involves two key transformations, the first of which is a Pd π-allyl mediated cyclisation for the construction of the dihydrobenzofuran skeleton. The second is a 6-endo-hydroarylation which yields the chromene as a precursor to rotenone. The synthesis of rotenone was achieved in 17 steps from resorcinol and constitutes the first stereoselective synthesis of this complex natural product.
- Georgiou, Kathy Hadje,Pelly, Stephen C.,de Koning, Charles B.
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p. 853 - 858
(2017/01/25)
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- Rotanone Analogs: Method of Preparation and Use
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The present invention provides rotenone analogs and methods of making and using them. Labeled with single photon and positron emitting isotopes, the rotenone analogs of the present invention are useful in, for example, clinical imaging applications as tracers to measure cardiac blood flow and detect regions of ischemia.
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- Synthesis of trans-B/C-Rotenoids: X-Ray and NMR Data for cis- and trans-Forms of Isorotenone
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Reduction of 6a,12a-didehydrorotenoids with diisobutylaluminium hydride gives clean 1,4-reduction leading to unstable trans-B/C-fusions, not previously known for enolisable rotenoids: they are epimerised to stable cis-forms under acid conditions.Applied initially to isorotenone, the method is extended to trans-B/C-deguelin, α-toxicarol, the 'core' rotenoid structure and the 6aS,12aR,5'R- and 6aR,12aS,5'R-rotenone stereoisomers. 1H and 13C NMR data are compared for the cis- and trans-forms and the geometry and conformations of the isorotenones are compared by X-ray analysis, providing insight into the reasons for the instability of the trans-forms.Reduction of the ridge-tile-like cis-isorotenone by sodium borohydride occurs from one face to give a cis-12α-hydroxy product, whilst the flatter trans-structure is attacked from both faces to give trans-12α- and 12β-hydroxy products.
- Begley, Michael J.,Crombie, Leslie,Hadi, Hamid bin A.,Josephs, Jonathan L.
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p. 2605 - 2614
(2007/10/02)
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- Biosynthesis of Rotenone and Amorphigenin. Study of the Origins of Isopropenyl-substituted Dihydrofuran E-Rings using Isotopically Labelled Late Precursors
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Whilst epoxidation of rot-2'-enonic acid is the most likely source of dalpanol in Amorpha fruticosa seedlings, administration of (5'R,6'S)-dalpanol shows that it is not an intermediate on the path to rotenone and amorphigenin.Labelled 4'-hydroxy- or 5'-hydroxy-rot-2'-enonic acid also do not qualify as intermediates in rotenone biosynthesis, but they are each converted into amorphigenin with chemospecific attack on the methyl group.By administration and re-isolation of amorphigenin from A. fruticosa seedlings, our earlier conclusion that hydroxylation ofrotenone to form amorphigenin proceeds with even label scrambling between C-7' and C-8', probably via an allylic radical, is confirmed.Competitive double-labelling experiments are employed to support a scheme in which rotenone derives directly from rot-2'-enonic acid by an enzyme-induced radical-type reaction without the intervention of an hydroxylated intermediate, and the two labelled hydroxyrot-2'-enonic acids are similarly cyclised using their methyl groups.The incorporations into amorphigenin of labelled 4- and 5-hydroxyrot-2'-enonic acids, both of which are shown to occur naturally in A. fruticosa, are similar, but only about one sixth that of rotenone.This, and our related biosynthetic work, rests on an extensive programme of isotopic labelling and reconstructive synthesis.Our earlier method for making -rotenone has been improved, and similar procedures adapted for - and -amorphigenin. 8'-Labelled rotenones are made by a positional interchange using addition of benzeneselenenyl chloride and elimination of the selenoxide, whilst -amorphigenin is made via addition of phenylselenophthalimide.Unlabelled amorphigenin can be isotopically labelled by oxidation to the aldehyde and reduction using sodium borodeuteride or borotritide and a method additional to those we have described earlier is given for tritium labelling of rot-2'-enonic acid. - and -Labelling in the 5'-position of 4'- and 5'-hydroxyrot-2'-enonic acids can be attained through the catalytic hydrogenolysis of amorphigenin though special methods must be used to scrub the samples totally free from the latter.Methods based on the hydrolysis of labelled 4'-bromorot-2'-enonic acid are also described, and 4'-tritium-labelled 4'-hydroxyrot-2'-enonic acid is made from unlabelled material, or from rot-2'-enonic acid, by simple oxidation/reduction methods.
- Bhandari, Prabha,Crombie, Leslie,Kilbee, Geoffrey W.,Pegg, Stephen J.,Proudfoot, Geoffrey,et al.
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p. 851 - 864
(2007/10/02)
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- Macrocyclic plant acaricides
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Compounds of the formula I STR1 in which either R is methyl and there is a double bond in the 9,10-position, or in which R is hydrogen and there is a single bond in the 9,10-position, are highly active against Acarina which damage plants.
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- Synthesis of Novel Labile Rotenoids with Unnatural trans-B/C Ring Systems
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6a,12a-Dehydrorotenoids are cleanly reduced in 1,4-fashion by DIBAL to give rotenoids having the unstable, unnatural, trans-B/C fusion, readily epimerised by acid to the cis-forms: an X-ray structure for (+/-)-trans-isorotenone confirms the nature of the ring fusion.
- Begley, Michael J.,Crombie, Leslie,Hadi, A. Hamid bin A.,Josephs, Jonathan L.
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p. 204 - 205
(2007/10/02)
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- Regioselective Ether Cleavages of Rotenoids: Spiro-ether Formation and Stereoselective Isotopic Labelling of (E)- or (Z)-Phenyl Methyl Groups in (6aS, 12aS)-Rot-2'-enonic Acid
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Treated with boron tribromide (-)-(6aS,12aS,5'R)-rotenone is converted first into a primary allylic bromide by ring-E cleavage, then into the 2-de-O-methyl and finally the 2,3-dide-O-methyl derivatives.With (6aS,12aS,5'R)-6',7'-dihydrorotenone and (6aS,12aS)-isorotenone, ring-E cleavage does not take place.The main reaction is 2-, followed by 2,3-demethylation: this supports a stereospecific pericyclic mechanism for the rotenone ring-E cleavage.Treatment of the geometrically pure (E)-bromide with cyanoboro-deuteride or -tritide leads to (E)-4'-labelled (6aS,12aS)-rot-2'-enonic acid without reduction of the 12-carbonyl group.By using -rotenone, (E)-rot-2'-enonic acid is accessible.Trimethylsilyl iodide can cleave the 2-methoxy-group of rotenonewithout rupturing ring E, and remethylation with - or -diazomethane represents a convenient method for preparing a general tracer molecule.On treatment with sodium hydride, 3-de-O-methylisorotenone (but not the 2-isomer) rearranges into a spiroether, thus confirming the position of initial de-O-methylation as deduced from 1H and 13C n.m.r. data.Because of this rearrangement, methylenation (NaH-CH2I2) of 2,3-dide-O-methylisorotenone gives mainly the methylenedioxy-spiro-ether, with small yields of methylenedioxy-rotenoid.Deuteriogenolysis of (-)-rotenone over palladium catalyst in (2H5)pyridine gives (E)-rot-2'-enonic acid, but experiments using rotenone indicate stereoselectivity rather than stereospecificity, ca. 12percent of (Z)--accompanying the major (E)-product.A similar specimen of rotenonic acid has been prepared.A hydrogenolysis route from amorphigenin, via rotenone, to (Z)-rot-2'-enonic acid is described.
- Carson, David,Crombie, Leslie,Kilbee, Geoffrey W.,Moffatt, Frank,Whiting, Donald A.
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p. 779 - 788
(2007/10/02)
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- Propynyl benzyl ethers
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Propynyl benzyl ethers having juvenile hormone-like activity which are 4-halogen, lower alkyl, lower alkoxy or propynyloxy substituted or 3,4-lower alkylenedioxy substituted and which can also be 3,5- and/or α-substituted, and insecticide compositions that include at least one propynyl benzyl ether and that can also include a conventional insect-poison.
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