Abstract: A method of making a compound of Formula VI: wherein Tr is a triphenyl group; R1, R2 and R3 are each independently selected from the group consisting of H, C1-C4 alkyl, C1-C4 alkoxy, aryl, heteroaryl, and arylalkyl; R4 is C2-C6 alkyl, and R5 and R6 are each independently H or C1-C4 alkyl, involves the step of reacting a compound of Formula V: with Tr-OH to produce a compound of Formula VI. The compounds of Formula VI are useful as intermediates in the manufacture of antibiotic agents. Methods of making compounds of Formula V, and intermediates made or used in the foregoing methods, are also described.