4630
J. Am. Chem. SOC.1984,106, 4630-4632
Table 11. TFA-Catalyzed Erythro-Selective Ketone Reduction with PhMeSH" ketone
run -
product (7% yield)b
time, h
threo: erythroC
Lithium aluminum hydride reduction (THF, 60 'C) of 2 gave l-ephedrine'* in 80% yield, while alkaline hydrolysis (KOH, MeOH-H20 (3:1), reflux) of 4 gave I-methoxamine,20an adrenergic vasopressor, in 83% yield. OH
OMe
OH
I
Me
I
I-ep hedrine
Me
Me NHCOOEt
NhCOOEt
(87)
I
Me
1
I-methoxam ine
