Pyrroglutamic acid

Addition of phenylmagnesium chloride to methyl pyroglutamate followed by reduction with borane to give racemic a,a-diphenyl-2-pyrrolidinemelhanol (3 steps, 51% yield from pyrroglutamic acid) that was then resolved as its O-acetylmandelate salt 10 give (R)- or (S)-a,a-diphenyl-2-pyrrolidinemethanol (2 steps, 3 recrystallizations, 30% yield from racemic a,a-diphenyl-2-pyrrolidinemethanol ref. 5f). 

Scheme 3.16 Synthesis of bicy H amidine from (S)-pyrroglutamic acid...

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