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Asymmetric Total Synthesis of (−)‐Lundurine B and Determination of Its Absolute Stereochemistry
Author(s) -
Nakajima Masaya,
Arai Shigeru,
Nishida Atsushi
Publication year - 2015
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201403407
Subject(s) - absolute configuration , chemistry , stereochemistry , cyclohexanone , total synthesis , amide , lithium amide , deprotonation , asymmetric carbon , lithium (medication) , absolute (philosophy) , enantioselective synthesis , organic chemistry , optically active , catalysis , epistemology , endocrinology , ion , philosophy , medicine
A total synthesis of the Kopsia tenuis alkaloid (−)‐lundurine B has been achieved. A quaternary chiral carbon has been created by an asymmetric deprotonation using a symmetric spiro cyclohexanone intermediate with a chiral lithium amide. The hexacyclic skeleton was sequentially constructed through metal‐mediated reactions. The absolute stereochemistry of intermediate 5 has been unambiguously established by X‐ray crystallographic analysis. This is the first description of the absolute stereochemistry of Kopsia tenuis alkaloids based on chemical synthesis.