Sparteine Group

Sparteine Group.—The new alkaloids calpurmenine (7) and its 2-pyrroloyl derivative (8) and the known compound 10,13-dihydroxylupanine were isolated from the South African plant Calpurnia aurea ssp. sylvatica but were absent from the Ethiopean C. aurea ssp. aurea.5 The structure of calpurmenine 12,13-dihydroxylupanine) was established by X-ray analysis of the ester (8).21 Another new alkaloid, 5,6-dehydro-a-isolupanine (9) was shown by g.l.c.- 

Bratek-Wiewiorowska, U. Rychlewska, and M. Wiewioraski, /. Chem. Soc., Perkin Trans. 2, 1979, 1469. 

Katrusiak, Z. Kaluski, and J. Wolinska-Mocydlarz, Acta Crystallogr., Sect. B, 1980, 36, 984. 

An earlier study of the catalytic reduction of 13-oxolupanine (cf. Vol. 8, p. 69) was interpreted in terms of intramolecular interaction between a protonated nitrogen atom and the carbonyl group at C-13. Direct evidence for this proposal has now been provided by c.d. data for a number of 13-oxosparteine derivatives, showing, for example, that ketone Cotton effects disappear in acid solution.25 

Matrine Group.—J -Ray studies of matrine alkaloids have continued in Russia with the examination of sophoridine,26 isosophoridine,27 tetrahydro-neosophoramine,28 and allomatrine and its N-oxide.29 The mass spectra of 

The conversion of lupanine into camoensidine may represent a biosynthetic pathway, and cleavage of the C-16 C-17 bond of a tetracyclic quinolizidine [cf. mamanine (3)] followed by carbon-carbon cyclization could lead to tetracyclic derivatives containing terminal piperidine rings. New alkaloids of this type have been obtained recently. Aloperine was first isolated from Sophora alopercuroides over forty years ago, and structure (12) has now been assigned to the alkaloid on the basis of spectral studies. Allylaloperine (13) is a constituent of the same species. Nitraramine (14) and 7V-hydroxynitraramine (15) from Nitraria schoberi are 

Ribas and co-workers have continued their investigations of retamine 7V-oxides and confirmed structures (17) and (18) for the N-l-oxide and for the iV-16-oxide, respectively, by i.r. and n.m.r. studies. Reaction of the iV-l-oxide (17) with methyl iodide in acetone at 70 C resulted in loss of the oxygen function and formation of retamine and formaldehyde. The N-oxide group in isomer (18) apparently is too 

Aslanov et al have extended their work on aphyllic acid (19). Oxidation of aphyllic acid with hydrogen peroxide gives the diacid (20), which can be converted into a 2,10-dioxosparteine. 

Matrine Group.—Further information is now available on the structure of neosophoramine cf. Vol. 6). Comparison of the mass spectra of sophoramine and neosophoramine shows that the two alkaloids are stereoisomers. The presence of an axial proton at C-5 in neosophoramine was apparent from the n.m.r. spectrum, and the absence of Bohlmann bands in the i.r. spectrum indicated a cis a/b ring junction. Since sophoramine has jS-hydrogen at C-5, C-6, and C-7 and in isosophoramine all three ring junctions are trans, neophoramine was assigned structure (21). 

The roots of Sophora flavescens contains isomatrine (22), a stereoisomer of matrine that was epimerized into a mixture of matrine and allomatrine. X-ray analysis established the structure and absolute configuration of the new alkaloid. Structure (23) has been proposed for lehmannine from Ammothamnus lehmanni as a result of spectral information and catalytic reduction of the alkaloid to matrine.  

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Lupanine-Sparteine Group.—A new alkaloid isolated from Echinosophora koreensis was shown to be N-(3-oxobutyl)cytisine (14) by means of spectroscopic studies and by its synthesis from the reaction of cytisine (13) and methyl vinyl... 

Lupanine-Sparteine Group.—A method has been developed for the separation and identification of microgram quantities of quinolizidine alkaloids by the sequential use of t.l.c. or g.l.c. combined with mass spectrometry. In all, 22 alkaloids have been identified by this technique. 

The ability of ditertiary bases of the sparteine group to complex with alkali-metals and alkaline-earth metals has been further investigated by carrying out the Reformatsky reaction in the presence of ( —)-sparteine. In all the cases examined, a partial asymmetric synthesis of (S)-hydroxy-esters was achieved, the optical purity of the products ranging from 34—98 %. 

In vitro tissue and cell cultures of lupin plants are not appropriate systems for the study of biosynthesis of lupin alkaloids, because the production ability by in vitro culture is rather low, i.e., 10 2 to lO times compared with that of differentiated plants. The production of the alkaloids of lupinine- and sparteine-groups by cell culture have been reported by us [59] and by Wink s group [60]. We have also successfully produced matrine in green callus culture and in multiple shoots of Sophora flavescens [61]. The producibility of matrine was positively correlated with the chloroplast formation. This indicates that the formation of carbon skeleton of matrine-type alkaloids also likely takes place in chloroplasts in plant cells as postulated in that of sparteine-type alkaloids [62]. 

Quinolizidine alkaloids, including sparteine group. For a tabulation of others not shown here, see [9]... 

The unstable CH TiCl [12747-38-8] from (CH3 )2 2n + TiCl forms stable complexes with such donors as (CH2)2NCH2CH2N(CH2)2, THF, and sparteine, which methylate carbonyl groups stereoselectively. They give 80% of the isomer shown and 20% of the diastereomer this is considerably more selective than the mote active CH MgBt (201). Such complexes or CH2Ti(OC2H2 methylate tertiary halides or ethers (202) as follows ... 

Owing to the use of lupin seeds for feeding animals, much attention has been given to the selection of species free from the more toxic alkaloids of the group, particularly sparteine, to methods of removing alkaloids from the seeds, a subjeet on which there is an extensive literature and to methods of estimating alkaloids in lupins on which a critical review has been published by Brahm and Andresen. ... 

Okamoto and his colleagues60) described the interesting polymerization of tri-phenylmethyl methacrylate. The bulkiness of this group affects the reactivity and the mode of placement of this monomer. The anionic polymerization yields a highly isotactic polymer, whether the reaction proceeds in toluene or in THF. In fact, even radical polymerization of this monomer yields polymers of relatively high isotacticity. Anionic polymerization of triphenylmethyl methacrylate initiated by optically active initiators e.g. PhN(CH2Ph)Li, or the sparteine-BuLi complex, produces an optically active polymer 60). Its optical activity is attributed to the chirality of the helix structure maintained in solution. 

Alkyldimethylphosphine-boranes 74 underwent enantioselective deprotonation employing (-)-sparteine/s-BuLi, followed by oxidation with molecular oxygen [91, 92] in the presence of triethyl phosphite (Scheme 12) to afford moderate yields of enantiomerically enriched alkyl(hydroxymethyl)methylphosphine-bo-ranes 76, with 91-93% ee in the case of a bulky alkyl group and 75-81% ee in the case of cyclohexyl or phenyl groups [93]. Except for the adamantyl derivative (in which the ee increased to 99%), no major improvement in the ee was observed after recrystallization. 

The enantioselective carbolithiation of cinnamyl derivatives described by the group of I. Marek and J.F. Normand [2] is one of the few reports on the use of sparteine as a catalytic activator of organoUthium carbanions... 

A similar method was later used by the group of Tomioka [10] for the asymmetric addition of thiazolylhthium 44 to prochiral aldimines (Scheme 10) for the preparation of (S)-Boc-Doe 46, a component of antileukemic marine natural product dolastatin 10. In this case, sparteine 1 was... 

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