title: Asymmetric total synthesis of (-)-saframycin A from L-tyrosine.
abstract: The asymmetric total synthesis of (-)-saframycin A, a natural antitumor product of the tetrahydroisoquinoline antitumor antibiotics family, has been accomplished by employing L-tyrosine as the starting chiral building block in 24 steps for the longest linear sequence in an overall yield of 9.7%. The key steps in the synthesis involve stereoselective intermolecular and intramolecular Pictet-Spengler reactions, which induced the correct stereochemistry at C-1 and C-11, respectively. The selective protection-deprotection protocol of an amino group in the two-step transformation from intermediate 10 to 12 and a hydroxyl group in the first two steps resulted in both high selectivity and efficiency of the synthetic route.
authors: State Key Laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100050, PR China.
authors: Wenfang
authors: W
authors: Dong
authors: Wei
authors: W
authors: Liu
authors: Xiangwei
authors: X
authors: Liao
authors: Baohe
authors: B
authors: Guan
authors: Shizhi
authors: S
authors: Chen
authors: Zhanzhu
authors: Z
authors: Liu