Aldol condensation reactions of chiral (dienone) tricarbonyliron complexes. 21. Enantioselective synthesis of the dienic polyols streptenols C and D (metabolites from Streptomyces Fimbriatus)
摘要:
The trimethylsilyl enol ether of (3,5-heptadien-2-one) tricarbonyliron 1 undergoes a highly stereoselective cross aldol reaction with TiCl4-coordinated beta-o.methoxybenzyloxypropanal yielding after deprotection the ketodiol complex 9. Direct decomplexation or decomplexation after totally metal induced stereoselective reduction to the triol 10, led to Streptenols C and D. The natural dextrorotatory enantiomers were obtained from the readily available pure (+)-1. (C) 1997 Elsevier Science Ltd.