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An Asymmetric Total Synthesis of Tupichilignan A using Donor–Acceptor Cyclopropanes: A Structural Revision of Tupichilignan A
Author(s) -
Kimura Yumi,
Sone Yoshitomo,
Saito Taichi,
Mochizuki Takehito,
Nishii Yoshinori
Publication year - 2017
Publication title -
asian journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.846
H-Index - 44
eISSN - 2193-5815
pISSN - 2193-5807
DOI - 10.1002/ajoc.201700222
Subject(s) - chemistry , cyclopropanation , cyclopropane , diastereomer , stereochemistry , total synthesis , enantioselective synthesis , stereoselectivity , decarboxylation , absolute configuration , lactone , acceptor , bicyclic molecule , catalysis , organic chemistry , ring (chemistry) , condensed matter physics , physics
An asymmetric total synthesis of tupichilignan A was achieved using enantioenriched donor–acceptor (D–A) cyclopropanes. The key steps include an asymmetric cyclopropanation using the Hayashi–Jørgensen catalyst, an oxy‐homo‐Michael reaction of a bicyclic D–A cyclopropane, an α‐benzylation of a γ‐lactone, a decarboxylation furnishing a trans ‐α,β‐dibenzyl‐γ‐lactone, a configurational inversion of a hydroxy chiral center via oxidation, and a final reduction, all of which occur with high stereoselectivity. The spectral data of the diastereomer previously identified in the literature as tupichilignan A were found to be inconsistent with the reported data for the natural product. On the basis of the spectral data of both of the synthesized diastereomers, the structure of tupichilignan A was revised, and the absolute configuration of the 7 position of tupichilignan A was changed from R to S .