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Synthesis of Enantiomeric Pure E‐Nor‐15‐azayohimbines
Author(s) -
Valls Nativitat,
Bonjoch Josep,
Del Alamo Carlos,
Bosch Joan
Publication year - 1992
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19920750110
Subject(s) - chemistry , tryptamine , derivative (finance) , enantiomer , condensation , pictet–spengler reaction , acetal , kinetic control , aqueous solution , organic chemistry , stereochemistry , medicinal chemistry , catalysis , biochemistry , physics , financial economics , economics , thermodynamics
A stereodivergent synthesis of enantiomerically pure E‐nor‐15‐azayohimbines via condensation of tryptamine with derivatives of pyroglutamate 4 is reported. When the Pictet ‐ Spengler reaction was induced in refluxing aqueous AcOH a nearly equimolar ratio of lactams 7 and 8 was obtained, whereas under kinetic control (TFA, room temperature) the trans ‐derivative 8 was the major product. In contrast, cyclization of amido acetal 12 with TsOH gave the cis ‐derivative 7 as preponderant component.