Methods of Non-a-Amino Acid Synthesis, 2nd Edition

185Aminocyclic andHeterocyclic Amino Acids

(77), as a 72:28 cis:trans mixture.

43

Similarly, reduction of the meta-derivative (78)

gave an 88% yield of 79.

43

A rhodium–aluminum catalyst was used to reduce the

ortho-amino-ester (80) to ethyl 2-aminocyclohexanecarboxylate (81), in 70% yield.

44

H

2

N

CO

2

NH

4

H

2

N

CO

2

H

CO

2

NH

4

NH

2

CO

2

H

NH

2

CO

2

Et

NH

2

CO

2

Et

NH

2

excess H

2

Ru(OH)Cl

3

/C

180 atm

160°C

excess H

2

EtOH

excess H

2

Ru(OH)Cl

3

/C

180 atm

160°C

76 77

78 79

80 81

Rh-Al

Other aromatic derivatives were reduced to 77 or 79 in a similar manner using a

nickel-rhenium catalyst.

45

A ruthenium-on-carbon/ruthenium oxide catalyst was used

for the preparation of 77 and 79

46

; a rhenium–alum ...