Concise synthesis of the core structures of saundersiosides.
A divergent synthesis of three core pentacyclic lactones of nine rearranged cholestane sapogenins, saundersiosides A-H (1-8) and candicanoside A (9), is reported. Key features include a one-flask CBS reduction/Brown hydroboration-oxidation, a SmI2-mediated intramolecular Reformatskii reaction, and an intramolecular transesterification. This synthesis provides a general strategy and key precursors for the collective synthesis of natural and designed saundersiosides. An efficient formal synthesis of candicanoside A is also achieved.
The Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Shou-Ling
SL
Cheng
The Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Xiao-Ling
XL
Jiang
The Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Yong
Y
Shi
The Key Laboratory of Synthetic Chemistry of Natural Substances, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.
Wei-Sheng
WS
Tian
D008958:Models, Molecular; D015394:Molecular Structure; D031442:Ornithogalum / Q000737:chemistry*; D012502:Sapogenins / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification
D012502:Sapogenins