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Additionsreaktionen an der alicyclischen Doppelbindung von Eburnamenin und Apovincamin
Author(s) -
Pfäffli Paul,
Hauth Hartmut
Publication year - 1978
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.19780610516
Subject(s) - chemistry , alicyclic compound , double bond , nucleophile , nucleophilic addition , medicinal chemistry , stereochemistry , organic chemistry , catalysis
Addition reactions on the alicyclic double bond of eburnamenine and apovincamine The addition of alcohols, amines or thiols on the 14, 15‐double bond of (−)‐eburnamenine ( 3a ) or (+)‐apovincamine ( 9a ) yielded the corresponding analogues of vincanol ( 5b‐h ), epivincanol ( 7b‐d ), vincamine ( 10b‐e ) and epivincamine ( 11b‐g ) with varying stereoselctivity. The reaction was achieved by addition of hydrogenbromide at −78° followed by nucleophilic attack, or in the (−)‐eburnamenine series also by direct addition of alcohols and thiols under acidic conditions. Without exception the analogues of epivincamine ( 11a‐g ) exhibited two carbonyl absorption bands in thier IR. spectra. (−)‐Eburnamenine ( 3a ) was obtained from (+)‐apovincamine ( 9a ) in a simple one pot reaction.