Patent ID: 7638639

Claim:
A compound of formula XI: wherein P is an amino-protecting group selected from benzyl, tert-butoxycarbonyl, trityl, benzyloxycarbonyl, p-methoxybenzyloxycarbonyl, 9-fluorenylmethoxycarbonyl, formyl, acetyl, trimethylsilyl, and tert-butyldimethylsilyl; G is selected from —CHO, —CH(OR f ) 2 , —CH 2 OH and —CH 2 -L, wherein each R f is independently C 1-6 alkyl or both R f groups are joined to form C 2-6 alkylene; and L is a leaving group; R 5 is selected from C 1-6 alkyl, C 2-6 alkenyl, C 2-6 alkynyl, C 3-6 cycloalkyl, and —CH 2 —R 8 ; wherein each alkyl, alkenyl, alkynyl and cycloalkyl group is optionally substituted with —OH or 1 to 3 fluoro substituents; each R 8 is independently selected from C 3-6 cycloalkyl, C 6-10 aryl, C 2-9 heteroaryl and C 3-6 heterocyclic; and e is 8 or 9; wherein each aryl, cycloalkyl, heteroaryl and heterocyclic group in R 5 and R 8 is optionally substituted with 1 to 3 substituents independently selected from C 1-4 alkyl, C 2-4 alkenyl, C 2-4 alkynyl, cyano, halo, —O(C 1-4 alkyl), —S(C 1-4 alkyl), —S(O)(C 1-4 alkyl), —S(O) 2 (C 1-4 alkyl), —NH 2 , —NH(C 1-4 alkyl) and —N(C 1-4 alkyl) 2 , wherein each alkyl, alkenyl and alkynyl group is optionally substituted with 1 to 5 fluoro substituents; and each —CH 2 — group in —(CH 2 ) e - is optionally substituted with 1 or 2 substituents independently selected from C 1-2 alkyl, —OH and fluoro; or a salt or stereoisomer thereof; provided that when L is chloro, P is not ethoxycarbonyl.