- PROCESS FOR THE MANUFACTURE OF LYSERGIC ACID
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Lysergic acid is formed in high yields and high quality by isomerizing paspalic acid in a phase separated mixture formed by paspalic acid and a concentrated aqueous metal hydroxide solution.
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Page/Page column 6-7
(2008/06/13)
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- Enantioefficient synthesis of α-ergocryptine: First direct synthesis of (+)-lysergic acid
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The first direct synthesis of (+)-lysergic acid (2a) suitable for scale-up has been achieved by the following reaction sequence. Bromoketones 4d or 4g were allowed to react with amine 5 followed by deprotection, and the resulting diketone 6c was transformed into the unsaturated ketone (±)-7 by the LiBr/Et3N system. Resolution afforded (+)-7, which was further transformed by Schoellkopfs method into the mixture of esters 2e and 2f. Upon hydrolysis the latter mixture afforded (+)-2a. The peptide part of α-ergocryptine (1) was prepared according to the Sandoz method; the stereoefficiency, however, has been significantly improved by applying a new resolution method and recycling the undesired enantiomer. Coupling the peptide part with lysergic acid afforded 1. Having synthetic (+)-7 in hand, we can claim the total synthesis of all the alkaloids which were prepared earlier from (+)-7 that had been obtained through degradation of natural lysergic acid.
- Moldvai, Istvan,Temesvari-Major, Eszter,Incze, Maria,Szentirmay, Eva,Gacs-Baitz, Eszter,Szantay, Csaba
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p. 5993 - 6000
(2007/10/03)
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