Patent ID: 7268229

Claim:
A compound of formula (XII) wherein R 7 is H, alkyl, heteroalkyl, aryl, or —CH 2 —C 6 H 4 OR 14 ; R 8 is H, alkyl, heteroalkyl, or aryl; R 9 is H, alkyl, heteroalkyl, aryl, or —C 6 H 4 OR 15 ; R 10 is —H, —CH 3 , or —CH(CH 3 ) 2 ; R 14 and R 15 are each independently a protecting group; and R 11 together with the oxygen atom to which it is attached is an ester or an acyloxymethyl ether; with the proviso that R 11 , R 14 , and R 15 are not all acetyl groups.