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Alkaloids by hydrolysis

I think that if you dry the lysergic acid (obtained from the ergot alkaloids by hydrolysis as described earlier) it will also work in methods A and B. This is how you dry lysergic acid dry under high vacuum at 140-145° for 2-3 hours. [Pg.60]

LSD is used as a drug of abuse and has potential medical applications. There are therefore forensic requirements to measure LSD and its isomer iso-LSD in body fluids including urine. LSD is considered a semisynthetic drug, being made from some naturally occurring ergot alkaloids by hydrolysis to lysergic acid, which is then reacted with diethylamine to produce LSD. [Pg.4392]

Three syntheses of 6,7-secoberbines have been carried out. Two of them involved degradation of the protoberberine alkaloids (63,65), and the third was a total synthesis (69). Takao and Iwasa (63) applied the von Braun reaction to tetrahydrocoptisine (39) to obtain the 6,7-seco bromide 63, which on treatment with dimethylamine, followed by hydrolysis, gave tetrahydro-corydamine (64). This tetrahydrobase 64, which was also produced from 56 by zinc in hydrochloric acid (63), was dehydrogenated to corydamine (56) (Scheme 15). [Pg.253]

The utilization of the Robinson annellation method for the synthesis of cory-nanthe-type alkaloids has been thoroughly investigated by Kametani and coworkers (149-152). The tetracyclic ring system was efficiently formed via the Michael addition of dimethyl 3-methoxyallylidenemalonate (247) to the enamine derived from 3,4-dihydro-1 -methyl-(3-carboline (150). Alkylation of 248, followed by hydrolysis and decarboxylation, resulted in a mixture of stereosiomeric enamides 250 and 251. Hydrogenation of 250 afforded two lactams in a ratio of 2 1 in favor of the pseudo stereoisomer 253 over the normal isomer 252. On the other hand, catalytic reduction of 251 gave 254 as the sole product in nearly quantitative yield. Deprotection of 254, followed by lithium aluminum hydride reduction, yielded ( )-corynantheidol (255) with alio relative configuration of stereo centers at C-3, C-15 and C-20. Similar transformations of 252 and 253 lead to ( )-dihydrocorynantheol and ( )-hirsutinol (238), respectively, from which the latter is identical with ( )-3-epidihydrocorynantheol (149-151.). [Pg.187]

Volume 75 concludes with six procedures for the preparation of valuable building blocks. The first, 6,7-DIHYDROCYCLOPENTA-l,3-DIOXIN-5(4H)-ONE, serves as an effective /3-keto vinyl cation equivalent when subjected to reductive and alkylative 1,3-carbonyl transpositions. 3-CYCLOPENTENE-l-CARBOXYLIC ACID, the second procedure in this series, is prepared via the reaction of dimethyl malonate and cis-l,4-dichloro-2-butene, followed by hydrolysis and decarboxylation. The use of tetrahaloarenes as diaryne equivalents for the potential construction of molecular belts, collars, and strips is demonstrated with the preparation of anti- and syn-l,4,5,8-TETRAHYDROANTHRACENE 1,4 5,8-DIEPOXIDES. Also of potential interest to the organic materials community is 8,8-DICYANOHEPTAFULVENE, prepared by the condensation of cycloheptatrienylium tetrafluoroborate with bromomalononitrile. The preparation of 2-PHENYL-l-PYRROLINE, an important heterocycle for the synthesis of a variety of alkaloids and pyrroloisoquinoline antidepressants, illustrates the utility of the inexpensive N-vinylpyrrolidin-2-one as an effective 3-aminopropyl carbanion equivalent. The final preparation in Volume 75, cis-4a(S), 8a(R)-PERHYDRO-6(2H)-ISOQUINOLINONES, il lustrates the conversion of quinine via oxidative degradation to meroquinene esters that are subsequently cyclized to N-acylated cis-perhydroisoquinolones and as such represent attractive building blocks now readily available in the pool of chiral substrates. [Pg.140]

The molybdenum-mediated arylamine cyclization was also applied to the total synthesis of pyrano[3,2-a]carbazole alkaloids (Scheme 26). Reaction of the 5-aminochromene 71 with the complex salt 62 affords the complex 72, which on oxidative cyclization provides girinimbine 73, a key compound for the transformation into further pyrano[3,2-a] carbazole alkaloids. Oxidation of 73 with DDQ leads to murrayacine 74, while epoxidation of 73 using meta-chloro-perbenzoic acid (MCPBA) followed by hydrolysis provides dihydroxygirinim-bine75 [113]. [Pg.134]

In the case of protein amino acid-derived alkaloids, the second obligatory intermedia is synthesized from the obligatory intermedia by chemical reactions. In the pelletierine synthesis pathway started with L-lysine, the second obligatory intermedia is A -piperidinium cation. It is formed by a Maimich reaction from A -piperidine (obligatory intermedia) and COSCoA. The second obligatory intermedia, by hydrolysis decarboxylation, produces pelletierine. [Pg.94]

Alternatively, the lactone mixture 7 and 8 may be ring opened by hydrolysis, followed by the separation of the corresponding carboxylic acids. The desired atropisomer may be converted into the product alkaloid, whereas the undesired isomer may be recycled by conversion back to the lactone mixture using oxalyl chloride for the acyl activation36. [Pg.580]

The properties and reactions of amino-alcohols, obtained largely by hydrolysis of naturally occurring alkaloids, were investigated primarily for the purposes of structural analysis and the preparation of physiologically active derivatives. Many authors have described acylation of pyrrolizidine alcohols with benzoyl chloride and acetic anhydride (see, e.g., refs. 83 and 101). Trachelanthamidine benzoate and p-aminobenzoate were prepared especially for testing of their physiological activity.102 The p-aminobenzoate was obtained by treatment of trachelanthamidine with p-nitrobenzoyl chloride and subsequent reduction of the nitro group with iron in 20% acetic acid. The compound exhibited an anesthetic activity close to that of cocaine. [Pg.355]

Rescinnamine (Moderil) is an alkaloid of the alseroxylon fraction of Rauwolfia root. Syrosingopine (Singoserp) is a preparation made from reserpine by hydrolysis and... [Pg.515]


See other pages where Alkaloids by hydrolysis is mentioned: [Pg.65]    [Pg.56]    [Pg.232]    [Pg.1339]    [Pg.300]    [Pg.457]    [Pg.65]    [Pg.56]    [Pg.232]    [Pg.1339]    [Pg.300]    [Pg.457]    [Pg.384]    [Pg.14]    [Pg.93]    [Pg.228]    [Pg.413]    [Pg.527]    [Pg.532]    [Pg.568]    [Pg.710]    [Pg.743]    [Pg.303]    [Pg.146]    [Pg.112]    [Pg.205]    [Pg.271]    [Pg.187]    [Pg.220]    [Pg.548]    [Pg.210]    [Pg.151]    [Pg.57]    [Pg.15]    [Pg.131]    [Pg.83]    [Pg.98]    [Pg.9]    [Pg.260]    [Pg.279]    [Pg.19]    [Pg.93]    [Pg.3]    [Pg.343]    [Pg.351]    [Pg.374]   
See also in sourсe #XX -- [ Pg.774 ]




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By hydrolysis

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