Patent ID: 6909014

Claim:
A compound of the formula IV: wherein: n is an integer ranging from 1 to 4; K 1 is —C(O)OH, —CHO, —C(O)OR 5 , R 1 and R 2 are independently selected from the group consisting of (C 1 -C 6 )alkyl, R 1 , R 2 , and the carbon to which they are attached are taken together to form a (C 3 -C 7 )cycloalkyl group; R 5 is selected from the group consisting of (C 1 -C 6 )alkyl, (C 2 -C 6 )alkenyl, (C 2 -C 6 )alkynyl, phenyl, and benzyl; W is selected from the group consisting of H and a hydroxy protecting group.