Synthesis of homochiral propargyl amines from tetrahydro-1,3-oxazines
摘要:
A direct method for the enantioselective synthesis of propargyl amines has been developed. 4-Substituted (S)-N-Boc-tetrahydro-1,3-oxazines were synthesised and the structure of one analogue determined by X-ray diffraction analysis. Ring-opening using alkynyl Grignard reagents in the presence of BF3.Et2O, followed by removal of the chiral directing group via oxidation and acid-catalysed retro-Michael reaction, gave the desired propargyl amines in good yield. (C) 1998 Elsevier Science Ltd. All rights reserved.