Asymmetric syntheses of (-)-isoretronecanol and (-)-trachelantamidine

作者：Brambilla Marta; Davies Stephen G^*; Fletcher Ai M; Roberts Paul M; Thomson James E

来源：Tetrahedron, 2014, 70(2): 204-211.

DOI：10.1016/j.tet.2013.11.094

• (-)-Isoretronecanol
• (-)-Trachelantamidine
• Lithium amide
• Conjugate addition
• Asymmetric synthesis
• Pyrrolizidine alkaloids

Short and concise total asymmetric syntheses of (-)-isoretronecanol and (-)-trachelantamidine are reported. Oxidative cleavage of tert-butyl (S,S,S,Z)-74N-benzyl-N-(alpha-methylbenzypamino]cyclohept-3ene-1-carboxylate, followed by hydrogenolysis promoted in situ cyclisation/reduction, which provided rapid access to the bicyclic core within (-)-isoretronecanol. Analogous treatment of the C(1)-epimer gave (--trachelantamidine. Overall, the syntheses of (-)-isoretronecanol and (-)-trachelantamidine were completed in eight and seven steps and 20 and 9.5% yield, respectively, from commercially available starting materials.

• 出版日期2014-1-14