ISSN:
0947-6539
Keywords:
allylations
;
allylsilanes
;
double stereodifferentiation
;
ephedrine
;
homoallylic alcohols
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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.
Additional Material:
2 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.1460020918
