A Bidirectional Approach to the Synthesis of a Complete Library of Adjacent-Bis-THF Annonaceous Acetogenins
作者:Sanjib Das、Lian-Sheng Li、Sunny Abraham、Zhiyong Chen、Subhash C. Sinha
DOI:10.1021/jo050697c
日期:2005.7.1
Thirty-six stereoisomers of bifunctional adjacent bis-THF (tetrahydrofuran) lactones have been synthesized, which can afford a complete library of the adjacent bis-THF Annonaceous acetogenins. The bis-THF lactones were synthesized, starting from the enantioselectively pure 8,9:12,13-(E,E and Z,E)-16-benzyloxy-5-hydroxy-hexadeca-1,4-olide, in a highly distereoselective manner using oxidative reactions, including rhenium(VII) oxides-mediated oxidative cyclization, Shi's asymmetric epoxidation, and Sharpless asymmetric dihydroxylation reactions. Using the nonsymmetrical bis-THF lactones, syntheses of two nonnatural acetogenins were achieved.
Highly Stereoselective Intramolecular Addition of a Hydroxyl Group to Vinylsilanes via 1,2-Silyl Migration<sup>1</sup>
Interplay of Cascade Oxidative Cyclization and Hydride Shifts in the Synthesis of the ABC Spiroketal Ring System of Pectenotoxin-4
作者:Timothy J. Donohoe、Radosław M. Lipiński
DOI:10.1002/anie.201208919
日期:2013.2.25
Concepts: The formation of stereochemically defined bis‐THF units through a double cyclization and a hydride‐shift‐initiated route to spiroketals is described (see scheme; Xc=chiral auxiliary). The resulting sequence has been used in a synthesis of the C1–16 fragment of the naturally occurring antitumor agent pectenotoxin‐4.