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Diastereo‐ and Enantioselective Synthesis of N ‐Protected 2‐Amino 1,4‐Diols by an Oxa Michael Addition/1,3‐Dipolar Cycloaddition Protocol
Author(s) -
Enders Dieter,
Haertwig Andreas,
Runsink Jan
Publication year - 1998
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199809)1998:9<1793::aid-ejoc1793>3.0.co;2-9
Subject(s) - chemistry , enantioselective synthesis , cycloaddition , diastereomer , nitrile , michael reaction , regioselectivity , 1,3 dipolar cycloaddition , stereochemistry , intramolecular force , amino esters , enantiomeric excess , chiral auxiliary , nitro , medicinal chemistry , organic chemistry , catalysis , alkyl
An enantioselective synthesis of N ‐protected amino diols has been accomplished by employing a diastereoselective inter‐ and intramolecular 1,3‐dipolar cycloaddition reaction of optically active nitrile oxides as a key step. The nitro alkane starting materials were obtained by diastereoselective oxa Michael addition of (1 R ,2 S )‐(–)‐ N ‐formylnorephedrine ( 1 ) to aliphatic ( E )‐nitro alkenes 2 , 6a , b ( de = 96 – ≥ 98%). Subsequent diastereo‐ and regioselective cycloaddition reactions to highly substituted 4,5‐isoxazolines 5a – e , 8a , b (52‐81%) and reductive ring opening led – after cleavage of the auxiliary – to amino diols 13 , 14 in good overall yields (27‐40%, over five steps) and with excellent diastereomeric and enantiomeric excesses ( de , ee ≥ 96%).