Patent ID: 7045309

Claim:
A compound represented by formula (I) wherein W is selected from the group consisting of H, halogen, azido and amino group; X is selected from the group consisting of O, S, N(H), CH 2 and CH; Y is selected from the group consisting of H, hydroxy, C 1-4 alkyl, C 1-4 alkoxy and halogen; R is selected from the group consisting of H, hydroxymethyl, C 1-4 alkyl, and C 1-4 alkoxy; R 1 is selected from the group consisting of O, NH and CH 2; R 2 represents a radical selected from the group consisting of —(CH 2 ) n —S—C(O)—R 4 and —(CH 2 ) n —S—S—R 4 , where n=1-4 and R 4 is a C 1-4 alkyl or aryl group and R 4 is optionally substituted with a halogen, amino, N-alkylamino, N,N-dialkylamino or C 1-4 alkoxy group and wherein each of the R 2 radicals may be the same or different; R 3 is O or S; and when X is CH the ring so formed is unsaturated and when X is CH 2 the ring so formed is saturated.