Reaction #78915

ord-a19ff513838e4c26b480bc7134194942

Reaction equation

$C=CC(C)(C)c1[nH]cnc1/C=C1\NC(=O)[C@H](Cc2ccccc2)NC1=O$

phenylahistin

phenylalanine

→

$C=CC(C)(C)c1[nH]cnc1/C=C1\NC(=O)[C@@H](Cc2ccccc2)NC1=O$

(+)-phenylahistin

Reactants

—

amino acid

$C=CC(C)(C)c1[nH]cnc1/C=C1\NC(=O)[C@H](Cc2ccccc2)NC1=O$

phenylahistin

phenylalanine

Reagents

None

Solvents

n-hexane ethanol

Conditions

Detailed conditions

See reaction.notes.procedure_details.

Workup

1
workup.ADDITIONa mixture of enantiomers in the ratio of approximately R
2
Other25° C

Procedure

It was also determined that phenylahistin has a chiral center at the C-10 position. Chiral HPLC analysis of the phenylalanine was conducted according to methods described in Larsen, T. O et al., Phytochemistry (1992) 31, 1613, under the following conditions: HPLC conditions: column; Crownpak CR(+) N4.0×150 mm (Daicel Chemical Industries, Ltd.), mobile phase; H2O (pH 2, adjusted with perchloric acid), flow rate; 0.8 ml/mn, detector; UV 8 200 nm. Phenylalanine was obtained from the acidic hydrolysate of the amorphous white powder of phenylahistin, see Yamazaki, M. et al., Tetrahedron Lett. (1975) 27. The phenylalanine obtained from the hydrolysate of phenylahistin was identified using an amino acid analyzer and by measurement of EI-MS [(m+H)+:166.2]); chrial HPLC indicated that the phenylahistin was a mixture of enantiomers in the ratio of approximately R:S=3.1. In order to examine the biological activity of each enantiomer, chiral resolution was carried out by chiral HPLC under the following conditions: column; Chiracel OD N4.6×250 mm (Daicel Chemical Industries, Ltd), mobile phase; n-hexane/ethanol=75/25, flow rate; 1.0 ml/min, temperature; 25° C. Absolute configuration was determined by analysis of phenylalanine obtained from (+)-phenylahistin using chiral HPLC.

Source

DOI: 10.6084/m9.figshare.5104873.v1Patent: US06713480B2uspto-grants-2004_03