17132-48-8Relevant articles and documents
Enantioselective total synthesis of (+)-amabiline
Senter, Timothy J.,Fadeyi, Olugbeminiyi O.,Lindsley, Craig W.
, p. 1869 - 1871 (2012/05/20)
The first total synthesis of (+)-amabiline, an unsaturated pyrrolizidine alkaloid from Cynoglossum amabile, is reported. This convergent, enantioselective synthesis proceeds in 15 steps (10-step longest linear sequence) in 6.2% overall yield and features
Absolute configuration and synthesis of β- and δ-lactones present in the pheromone system of the giant white butterfly Idea leuconoe
Stritzke, Katja,Schulz, Stefan,Nishida, Ritsuo
, p. 3884 - 3892 (2007/10/03)
Males of the giant white butterfly Idea leuconoe release a complex mixture of compounds during courtship. Besides alkaloids, aromatics, terpenoids and hydrocarbons, several lactones have been identified in the pheromone bouquet. Two simple stereoselective methods to create the lactones in good enantiomeric excesses have been developed. The generation of the stereocenters of the β-lactones la and lb is based on a controlled C-C coupling by a Horner-Wadsworth-Emmons approach, followed by asymmetric dihydroxylation, whereas the synthesis of the δ-lactone 3b uses an enantioselective hydrogenation of a dioxoalkanoate precursor. The absolute configurations of the natural lactones 1a, 1b and 3b were determined by gas chromatography on a chiral stationary phase. Both 1a and 1b are of (S,S) configuration, suggesting their biosynthetic origin from (-)-viridifloric acid (7a) or (-)norviridifloric acid (7b), respectively. In contrast, natural 3b is a mixture of all enantiomers, in which the (5S,7S) enantiomer dominates. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002.
Pyrrolizidine Alkaloid Biosynthesis. Synthesis of 3H-Labelled Trachelanthamidine and Isoretronecanol and their Incorporation into Three Pyrrolizidine Bases (Necines)
Kunec, Ellen K.,Robins, David J.
, p. 1437 - 1441 (2007/10/02)
(+/-)-Isoretronecanol (22) and (+/-)-trachelanthamidine (24) were prepared by 1,3-dipolar cycloaddition of N-formylproline with ethyl propiolate followed by reduction steps.These 3H-labelled 1-hydroxymethylpyrrolizidines together with putrescine were fed to Senecio isatideus which produces retrorsine (1); S. pleistocephalus which yields rosmarinine (8); and Cynoglossum officinale which affords echinatine (5).The double labelling experiments demonstrated that isoretronecanol is incorporated much more efficiently into rosmarinine than into retrorsine or echinatine, whereas trachelanthamidine is a much more efficient precursor for retrorsine and echinatine.Base hydrolysis of retrorsine and echinatine labelled with trachelanthamidine and of rosmarinine labelled with isoretronecanol established that most of the 3H-label was in the base portions, retronecine (2), heliotridine (6), and rosmarinecine (9), respectively.Further degradation of retronecine and rosmarinecine showed that most of the radioactivity was confined to the β-alanine (4) portion.The biosynthetic pathways to isoretronecanol and trachelanthamidine apparently diverge prior to the formation of these 1-hydroxymethylpyrrolizidines, probably during the cyclisation of an immonium ion (14) to form the 1-formylpyrrolizidines (15) and (17).
Pyrrolizidine Alkaloid Analogues. Synthesis of 11-Membered Macrocyclic Diesters of (+)-Heliotridine
Hagan, Desmond B.,Robins, David J.
, p. 1165 - 1168 (2007/10/02)
The first synthesis of macrocyclic diesters incorporating (+)-heliotridine has been achieved.Treatment of (+)-heliotridine (1) with different glutaric anhydride derivatives produced mainly the corresponding 9-monoesters of heliotridine.Lactonisation was carried out after formation of the pyridine-2-thiol esters to give a range of 11-membered macrocyclic diesters of heliotridine.The structures of these new pyrrolizidine alkaloid analogues were established by comparison of their (1)H n.m.r. and mass spectra with those of natural macrocyclic pyrrolizidine alkaloids.Attempts to make 10-membered macrocyclic diesters of heliotridine were unsuccessful.
Parsonine,a Pyrrolizidine Alkaloid from Parsonsia leavigata
Abe, Fumiko,Yamachi, Tatsuo
, p. 4661 - 4663 (2007/10/02)
A pyrrolizidine alkaloid was isolated from the stems of Parsonsia laevigata ALSTON, a plant upon which the larvae of Idea leuconoe ERICHSON feed, and its structure was determined to be 1-(2'S,3'S)-2',3'-dihydroxi-2'-isopropylbutanoyloxymethyl-5,6-dihydropyrrolyzin-7-one.Keywords---Parsonsia laevigata; Apocynaceae; pyrrolyzidine alkaloid; 2,3-dihydroxy-2-isopropylbutanoic acid; viridifloric acid; 1-hydroxymethyl-5,6-dihydropyrrolyzin-7-one;danaidone homologue
Synthesis of pyrrolizidine alkaloids indicine, intermedine, lycopsamine, and analogues and their N-oxides. Potential antitumor agents
Zalkow,Glinski,Gelbaum,Fleischmann,McGowan,Gordon
, p. 687 - 694 (2007/10/02)
(-)- and (+)-trachelanthic and (-)- and (+)-viridifloric acids were synthesized and their isopropylidene derivatives were regiospecifically coupled, at C-9, with (-)-retronecine (2) obtained by hydrolysis of monocrotaline (1), isolated from Crotalaria spectabilis. Hydrolysis, followed by oxidation, led to the N-oxides of indicine (7), intermedine (13), lycopsamine (15), and the new nonnatural product 16, respectively. Each of these analogues was screened in the P388 lymphocytic leukemia system at the same time as indicine N-oxide, and the results were compared. Other related analogues were prepared and similarly screened and the results compared with those from indicine N-oxide.
