Patent ID: 8642798

Claim:
A diastereomeric mixture of: (A) an optically active compound having the formula: wherein R 8 is —C 1 -C 6 alkyl, -phenyl, or -benzyl; R 9 is —H, —C 1 -C 6 alkyl, -allyl, -phenyl, or -benzyl; R 10 is —H, —C 1 -C 6 alkyl, -allyl, -phenyl, or -benzyl, or R 10 and R 11 are taken together to form: R 11 is —H, —C 1 -C 6 alkyl, -allyl, -phenyl, or -benzyl, or R 11 and R 12 are taken together to form —(CH 2 ) 3 —; and R 12 is —H, —C 1 -C 6 alkyl, or -phenyl; and (B) an optically active compound having the formula: wherein R 8 , R 9 , R 10 , R 11 , and R 12 of the optically active compound of formula (IIIA) and of the optically active compound of formula (IIIB) are the same.