Patent ID: 7576234

Claim:
A method of preparing a compound represented by Structural Formula (VII): or a salt thereof wherein: R 6 is —H or a substituted or unsubstituted alkyl group; and R 7 is a substituted or unsubstituted alkyl group; comprising the steps of: a.) reacting a nucleophile, A—S—Z, with a compound represented by Structural Formula (VIII): wherein: A is —H; R 8 is —H or a substituted or unsubstituted alkyl group; Z is a protecting group; and R 6 is as defined above; thereby forming a compound represented by Structural Formula (IX): b.) reacting the compound represented by Structural Formula (IX) with one or more bases, R 7 X, and a phase transfer catalyst, wherein X is a leaving group; and R 6 , R 7 , R 8 , and Z are as defined above; thereby forming a compound represented by Structural Formula (X): c.) converting the compound represented by Structural Formula (X) into a compound represented by Structural Formula (XI): d.) removing Z from the compound represented by Structural Formula (XI), thereby forming the compound represented by Structural Formula (VII).