24182-47-6Relevant academic research and scientific papers
Lipase-catalyzed synthesis of ethyl (R)-2-benzyloxy-2-isopropylhydrogenmalonate: A useful combination of chemical synthesis with enzymatic methods
Ding, Jing,Yang, Zhijun,Zhao, Yu,Fang, Weizhen,Lu, Qun
, p. 763 - 767 (2019/04/29)
Ethyl (R)-2-benzyloxy-2-isopropylhydrogenmalonate is a key intermediate for the synthesis of the side chain in ergopeptines. In this work, we adopted a method to prepare enantiomeri-cally pure title monoester via immobilized Candida antarctica lipase B (Novozym 435)-catalyzed hydrolysis of the corresponding diester.
Enantioefficient synthesis of α-ergocryptine: First direct synthesis of (+)-lysergic acid
Moldvai, Istvan,Temesvari-Major, Eszter,Incze, Maria,Szentirmay, Eva,Gacs-Baitz, Eszter,Szantay, Csaba
, p. 5993 - 6000 (2007/10/03)
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.
