Synlett 1991; 1991(9): 618-620
DOI: 10.1055/s-1991-20816
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Controlled Opening-Cyclisation Reactions of the Macrolactone of Ivermectin Aglycones

Jean Pierre Férézou* , Marc Julia, Lu Wei Liu, Ange Pancrazi
  • *Laboratoire de Chimie, École Normale Supérieure, 24 rue Lhomond, F-75231 Paris Cedex 05, France
Further Information

Publication History

Publication Date:
07 March 2002 (online)

The aglycone of 5-O-tert-butyldimethylsilyl 22,23-dihydroavermectin B1a has been treated with various alcohols (orthiols) in the presence of titanium(IV) isopropoxide to give the corresponding secoesters without isomerisation of the crucial Δ3 double bond nor epimerization at C - 2. The β-(trimethylsilyl)ethyl and allyl secoesters were then cleanly converted into the parent B1a 5-O-tert-butyldimethylsilyl aglycone.

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