S-coniceine

S-Coniceine (2-piperolidine), is prepared by the action of sulphuric acid on bromoconiine. It has a multiplicity of names. Itw, s first characterised by Lellmann, who assigned to it formula (III) and was synthesised by Loffler and Kaim who distilled piperidylpropionic acid to obtain piperolid-2-one (IV) and reduced this to 2-piperolidine (III) which proved... 

Indolizidine is the alkaloid S-coniceine and this nucleus has been observed in several groups of alkaloids. Since the chemistry of alkaloids deriving from indolizidines and partially unsaturated indolizidines is reported regularly (B-81MI30800, B-79MI30800), only selected examples will be taken from the natural products field. Structurally more complex alkaloids such as (217), (218) and indolizidine aza steroids (81H(16)1093,81H(16)1097), which may often be assigned to other groups of alkaoids as well, are not mentioned. 

S-Coniceine has been prepared in several steps that include the... 

S-Coniceine boils at 168-169°and melts at 41°,d 0.8519, [ajp—50.64°. It forms crystalline salts such as the bitartrate, m.p. 62-63° and others (Table 3). It readily reduces potassium permanganate and when a solution of its hydrochloride is treated with sodium nitrite, it gives rise to a nitroso derivative so that it is an unsaturated secondary base. Since the... 

Two new syntheses of -coniceine (L) have been reported. In one 74), l-methyl-2-pyrrolidone and 4-methoxybutylmagnesium bromide yield the dihydropyrrole LI which is reduced to the pyrrolidine, converted to the bromo compound, cyclized, and the resulting methobromide thermally decomposed to give S-coniceine (L). 

In the other synthesis 75), the Leuckart reaction on y-ketosuberic acid gave 3-(6-oxopiperidyl)propionic acid which on heating yielded LII. Lithium aluminum hydride reduction of LII gave S-coniceine (L). 

Cobalt(III) fluoride, 397 Cobalt(II) phthalocyanine, 102-103 Collman s reagent, 174-175 6-Coniceine, 398 Coniferyl alcohol, 351 Cope rearrangement, 31,311 Copper(ll) acetate, 103, 211 Copper(fl) acetate-Iron(II) sulfate, 103-104 Copper(I) bromide-Diinethyl sulfide, 104-105... 

Coniceine (Hofmann s a-coniceine) is obtained by the action of sulfuric acid on bromoconiine (132). It is a fully saturated tertiary base... 

The y-coniceine and coniine are generally the most abundant, and they account for most of the plant s acute and chronic toxicity. These alkaloids are synthesized by the plant from eight acetate units from the metabolic pool, forming a polyketoacid which cyclizes through an aminotransferase and forms gamma-coniceine as the parent alkaloid via reductiOTi by an NADPH-dependent reductase. 

The third paper of Fairbaim s series brings proof of existence of such substances in developing fruit (Fairbaim and Ali, 1968a). Three types of unidentified compounds have been separated on the basis of solubility in water, in 70% ethanol, and in pure ethanol. Upon hydrolysis by acid or alkali, all three groups of compounds yielded Dragendorff-positive substances. Some were not identified, but coniine and y-coniceine were positively detected. 

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