Stereodivergent Access to Cis- and Trans-3,5-Disubstituted 1,4-Thiazane 1-Oxides by Cyclization of Homochiral β-Amino Sulfoxides and Sulfones. The Preparation of Isomeric Ant Venom Alkaloids
摘要:
Intramolecular conjugate additions of homochiral (E)-1-alkenyl 2-aminoalkyl sulfoxides and sulfones were investigated. The relative position of the 3,5-substituents of the resulting 1,4-thiazane oxides was found to be dependent on the oxidation state of the sulfur atom, demonstrating a simple and highly stereodivergent synthetic protocol. Selected cis- and trans-3,5-disubstituted 1,4-thiazane dioxides were converted to cis- and trans-2,5-disubstituted pyrrolidines, known ant venom alkaloids.
Sulfenate Substitution as a Complement and Alternative to Sulfoxidation in the Diastereoselective Preparation of Chiral β-Substituted β-Amino Sulfoxides
作者:Stefan C. Söderman、Adrian L. Schwan
DOI:10.1021/jo302769b
日期:2013.2.15
absolute configuration of the products makes the sulfenate protocol complementary to other existing preparations, including the commonly employed sulfoxidation of β-amino sulfides. The reactivity of N-Boc-protected 2-benzyl-2-aminoethyl iodide was found to be superior to the less stericallyencumbered n-butyl iodide. A transition state model is proposed to account for the stereochemistry of the products
Stereodivergent Access to <i>Cis-</i> and <i>Trans</i>-3,5-Disubstituted 1,4-Thiazane 1-Oxides by Cyclization of Homochiral β-Amino Sulfoxides and Sulfones. The Preparation of Isomeric Ant Venom Alkaloids
作者:Stefan C. Söderman、Adrian L. Schwan
DOI:10.1021/ol4023003
日期:2013.9.6
Intramolecular conjugate additions of homochiral (E)-1-alkenyl 2-aminoalkyl sulfoxides and sulfones were investigated. The relative position of the 3,5-substituents of the resulting 1,4-thiazane oxides was found to be dependent on the oxidation state of the sulfur atom, demonstrating a simple and highly stereodivergent synthetic protocol. Selected cis- and trans-3,5-disubstituted 1,4-thiazane dioxides were converted to cis- and trans-2,5-disubstituted pyrrolidines, known ant venom alkaloids.