Scalable Synthesis And Isolation Of The Four Stereoisomers Of Methyl 1-Amino-3-(4-Bromophenyl)Cyclopentanecarboxylate, Useful Intermediates For The Synthesis Of S1p1 Receptor Agonists

The individual isomers of methyl 1-amino-3-(4-bromophenyl)cyclopentanecarboxylate are useful intermediates for the synthesis of SIPI receptor agonists. Herein we describe a scalable synthesis and isolation of each of the four stereoisomers of this compound in gram quantities with >98% ee and de. The utility of this approach is demonstrated by the synthesis of ((1R,3R)-1-amino-3-(4-octylphenyl)cyclopentyl)methanol in 7 steps, 11% overall yield, and >98% ee and de.