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Synthesis of Enantiopure Homoallylic Alcohols and Ethers by Diastereoselective Allylation of Aldehydes
Author(s) -
Tietze Lutz F.,
Schiemann Kai,
Wegner Christoph,
Wulff Christian
Publication year - 1996
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.19960020920
Subject(s) - enantiopure drug , reagent , trimethylsilyl , trifluoromethanesulfonate , chemistry , yield (engineering) , organic chemistry , aldehyde , ether , catalysis , ammonia , salt (chemistry) , alcohol , enantioselective synthesis , materials science , metallurgy
Enantiopure homoallylic alcohols 5 , which are important building blocks in organic synthesis, are obtained with an ee of greater than 99% and a yield of 75–95% by cleavage of the secondary homoallylic ethers 4 using sodium in liquid ammonia. The ethers 4 are formed with excellent diastereoselectivity and in 52–89% yield by treatment of the aldehydes 1 with the trimethylsilyl ether of N ‐trifluoroacetylnorpseudoephedrine ( 2 ) in the presence of a catalytic amount of TMS triflate or TMS borontriflate, followed by addition of allylsilane 3 . Nearly all achiral aliphatic aldehydes employed gave a diastereoselectivity of over 99:1. With the chiral aldehydes 24 , the difference between matched and mismatched pairs was low; this reveals that there is strong reagent control.