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Total Synthesis of (–)‐Fasicularin and (–)‐Lepadiformine A Based on Zn‐Mediated Allylation of Chiral N ‐ tert ‐Butanesulfinyl Ketimine
Author(s) -
Mei SanLin,
Zhao Gang
Publication year - 2010
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200901422
Subject(s) - chemistry , epoxide , total synthesis , dihydroxylation , sharpless asymmetric dihydroxylation , stereoselectivity , enantioselective synthesis , alcohol , intramolecular force , reagent , organic chemistry , combinatorial chemistry , stereochemistry , medicinal chemistry , catalysis
Abstract The stereoselective total synthesis of fasicularin ( 1 ) andlepadiformine A ( 2 ) is described, which features the utilization of a Zn‐mediated allylation of a chiral, aliphatic, N ‐ tert ‐butanesulfinyl ketimine to construct the amino‐substituted quaternary carbon center in good yield and with excellent diastereoselectivity. The azaspirocyclic scaffold was installed sequentially by a Sharpless dihydroxylation and an internal epoxide‐opening reaction, and this scaffold was further converted into common intermediate 5 . Removing the tosyl (Ts) protecting group of 5 and reductively aminating usingLuche's reagent completed the synthesis of (–)‐fasicularin ( 1 ), while reducing 5 using L ‐selectride, deprotecting the Ts group, and finishing with an intramolecular amino alcohol cyclocondensation completed the total synthesis of (–)‐lepadiformine A ( 2 ).