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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/Et(3)N system. Resolution afforded (+)-7, which was further transformed by Schöllkopf's method into the mixture of esters 2e and 2f. Upon hydrolysis the latter mixture afforded (+)-2a. The peptide part of alpha-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.

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Organic chemistry Z 0200 Synthetic Route to Ergot Alkaloids -[37 refs.]. -(MOLDVAI, I.; TEMESVARI-MAJOR, E.; INCZE, M.; DOERNYEI, G.; SZENTIRMAY, E.; SZANTAY*, C.; Helv. Chim. Acta 88 (2005) 6, 1344-1356; Chem. Res. Cent., Hung. Acad. Sci., H-1525 Budapest, Hung.; Eng.) -S. Adam 40-257

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