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Asymmetric Syntheses via Heterocyclic Intermediates, XXXIII. Asymmetric Synthesis of (Diastereomerically and Enantiomerically Virtually Pure) Methyl (2 R ,3 S )‐ threo ‐2‐Amino‐3‐hydroxy‐4‐alkenoates by the Bislactim Ether Method
Author(s) -
Schöllkopf Ulrich,
Bardenhagen Jürgen
Publication year - 1987
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.198719870343
Subject(s) - chemistry , diastereomer , hydrolysis , stereochemistry , derivative (finance) , enantioselective synthesis , ether , organic chemistry , medicinal chemistry , catalysis , financial economics , economics
The titanium derivative 4a of the bislactim ether 1a from cyclo ‐( L ‐Val‐Gly) reacts with α,β‐unsaturated aldehydes 5 exclusively by 1,2‐addition in a highly diastereoselective mode to give virtually only the (2 R ,1′ S ) diastereomers of type 6 . Upon hydrolysis these furnish the methyl (2 R ,3′ S )‐ threo ‐2‐amino‐3‐hydroxy‐4‐alkenoates of type 11–13 which are essentially diastereomerically and enatiomerically pure.