A Convenient Triisobutylaluminium (TIBAL)-Promoted Johnson-Claisen Approach to γ,δ-Unsaturated Alcohols
作者:Ross McGeary、Kelly Cosgrove
DOI:10.1055/s-0029-1217382
日期:2009.7
Mixed ortho esters derived from allylic alcohols undergo methanol elimination in the presence of triisobutylaluminium (TIBAL) at room temperature to form mixed ketene acetals. TIBAL then promotes immediate Claisen rearrangement of these intermediates, and subsequent reduction of the ester products, to give unsaturated γ,δ-primary alcohols in a convenient, one-pot procedure.
Pd(0)-Catalyzed Oxy- and Aminoalkynylation of Olefins for the Synthesis of Tetrahydrofurans and Pyrrolidines
作者:Stefano Nicolai、Jérôme Waser
DOI:10.1021/ol2029383
日期:2011.12.2
The first Pd(0)-catalyzed intramolecular oxy- and aminoalkynylation of nonactivated olefins is reported. The reaction gives access to important tetrahydrofuran and pyrrolidine heterocycles with high diastereoselectivity. The unique synthetic potential of acetylenes is further exploited to access key building blocks for the synthesis of bioactive natural products.
A Bicyclo[3.2.0]hept-3-en-6-one Approach to Prostaglandin Intermediates
作者:Emanuela Marotta、Paolo Righi、Goffredo Rosini
DOI:10.1021/ol006664v
日期:2000.12.1
6-benzyloxymethyl-7-hydroxy-2-oxabicyclo [3.3.0]octan-3-one (1), a Corey lactone derivative, and 6-exo-benzyloxymethyl-2-oxabicyclo[3.3. 0]oct-7-en-3-one (2), have been obtained stereoselectively through the bicyclo[3.2.0]hept-3-en-6-one approach via 5-benzyloxymethyl-3-hydroxy-6-heptenoic acid, easily accessible from the inexpensive monoprotected cis-2-butene-1,4-diol.