Patent ID: 7723512

Claim:
A compound represented by formula I: wherein R 1 is optionally substituted aralkyl, —Si(R 7 ) 3 , —C(O)R 4 , —CO 2 R 4 , or —C(O)(NR 8 )R 4 ; R 2 represents independently for each occurrence H, alkyl, or halogen; R 3 , R 4 , and R 7 each represent independently for each occurrence alkyl, aryl, or aralkyl; R 5 is —Si(R 7 ) 3 , —C(O)R 4 , —CO 2 R 4 , or —C(O)(NR 8 )R 4 ; R 8 represents independently for each occurrence H, alkyl, aryl, or aralkyl; R 9 represents independently for each occurrence H or alkyl; and the stereochemical configuration at any stereocenter of a compound represented by I is R, S, or a mixture of these configurations.