Alkaloids tropane alkaloids

Steroidal Alkaloids and Steroidal Glycoalkaloids Norditerpenoid Alkaloids Pyrrolizidine Alkaloids Indolizidine and Polyhydroxy Alkaloids Tropane Alkaloids Glycosides... 

L-ornithine Ornithine-derived alkaloids True alkaloids Pyrrolidine alkaloids Tropane alkaloids Pyrrolizidine alkaloids... 

Biologic Background Isoquinoline Alkaloids Terpenoid Indole Alkaloids Tropane Alkaloids Purine Alkaloids... 

PYRROLIDINE ALKALOIDS PYRROLIZIDINE ALKALOIDS TROPANE ALKALOIDS... 

Tropane alkaloids Tropane alkaloids Quinine Indole alkaloids Calystegins Glycoalkaloids... 

The wM-diacetate 363 can be transformed into either enantiomer of the 4-substituted 2-cyclohexen-l-ol 364 via the enzymatic hydrolysis. By changing the relative reactivity of the allylic leaving groups (acetate and the more reactive carbonate), either enantiomer of 4-substituted cyclohexenyl acetate is accessible by choice. Then the enantioselective synthesis of (7 )- and (S)-5-substituted 1,3-cyclohexadienes 365 and 367 can be achieved. The Pd(II)-cat-alyzed acetoxylactonization of the diene acids affords the lactones 366 and 368 of different stereochemistry[310]. The tropane alkaloid skeletons 370 and 371 have been constructed based on this chemoselective Pd-catalyzed reactions of 6-benzyloxy-l,3-cycloheptadiene (369)[311]. 

Of the other tropane alkaloids, convolvine (veratroylnortroplne), convolamme (veratroyltropine) and a number of their derivatives have been examined. All are stated to be local anaesthetics. ... 

Tropane Group. SolanaceOus Alkaloids, Convolvine and Allied Alkaloids, Dioscorine, Alkaloids of Coca Leaves (Erythroxylon coca). ... 

Biosynthesis of tropan alkaloids hyosciamine and scopolamine by isomerization of alkaloid littorine in Datura. stramonium and related species 98CSR207. 

A divergent synthesis of tropane alkaloid ferruginine was reported by Node and coworkers [59]. The P-ketoester intermediate was prepared by a novel PLE-catalyzed asymmetric dealkoxycarbonylation (hydrolysis followed by a decarboxylation) of a symmetric tropinone-type diester (Figure 6.12). Dimethyl sulfoxide was added to the phosphate buffer pH 8 (1 9) to reduce the activity of PLE and prevent over-deal-koxycarbonylation leading to tropinone. 

Aziridinocyclopropanes 163 derived from 2-phenylsulfonyl-l,3-dienes undergo BF3-induced rearrangement to bicyclic amines 165, which feature the skeleton of the tropane alkaloids. The reaction proceeds via cyclopropyl carbinyl cation 164, an intermediate also invoked in the analogous epoxide rearrangements. Trapping by fluoride ion is a competing pathway <96TL3371>. 

Lawson, G., Ostah, N., and Woolley, J.G., MS/MS smdies of tropane alkaloids Detection and determination of stmctnre, m Applications of Modem Mass Spectrometry in Plant Science Research, Newton, R.P. and Walton, T.J., Eds., Clarendon Press, New York, 1996, chap. 16. 

The tropane alkaloids have been reviewed on five earlier occasions in this series (1-5). Since the last review in 1977 the number of known structures has grown markedly, to a present count of 139. In this chapter, the literature is covered up to the end of 1986. 

The tropane alkaloids are a well-recognized group of structurally related natural products. Long before elucidation of the structures, the mydriatic and anesthetic action of several compounds was exploited (6). The very extensive literature covering the pharmacological properties of the tropane alkaloids will be considered only briefly in this chapter. Readers with a deeper interest in the subject are referred to other publications (7-14) and to the references given in Section VII. 

The tropane alkaloids contain as a common structural element the azabicyclo [3.2.1] octane system, and the systematic name of tropane is 8-methyl-8-azabicyclo [3.2.1] octane (Fig. 1). Contradictory results concerning the C-6 and/or C-7 substitution of several C-3,C-6- and C-3,C-7-disubstituted and C-3,C-6,C-7-trisubstituted tropane alkaloids have been presented in the literature. In many cases both optical antipodes of these tropane alkaloids are known, either separately or as a racemic mixture. 

Applying the uniform numbering system presented in Fig. 1, most disubstituted tropane alkaloids that in the literature have been designated as C-3,C-6 disubstituted become C-3,C-7 disubstituted. The same principle, where applicable, is applied to the C-3,C-6,C-7 trisubstituted tropane alkaloids. 

The tropane alkaloids occur mainly in the plant family Solanaceae but are also found in the families Convolvufaceae, Erythroxylaceae, Proteaceae, and Rhizophoraceae. In addition, the presence of tropane alkaloids has occasionally been indicated in the families Euphorbiaceae and Cruciferae (cf. Tables II and III). For a detailed account of the distribution of tropane alkaloids among species, interested readers should consult Refs. (15-23) and references therein. 

Eight dimeric tropane alkaloids (132-139) have been found so far. 

Botanical Classification of Plants Containing Tropane Alkaloids"... 

C22H25N04 109 3a-Hydroxy-4a-hydroxybenzyl-7/ -benzoyloxy-tropane (alkaloid KD-F) P 5,22,63... 

A number of new synthetic approaches to the tropane skeleton have been developed during recent years. The more characteristic ones are described in this section. In order to provide a representative picture of the whole field, a few of the earlier syntheses, starting from the classic ones of Willstatter and Robinson, are briefly reviewed. The earlier methods based on the transformation of the preformed tropane skeleton are noted only occasionally. However, the recently developed syntheses of the proteaceous tropane alkaloids based on new C-acylation methods for tropinone (124) are included. 

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