Synthesis of a new (1R)-(-)-myrtenal-derived dioxadithiadodecacycle and its use as an efficient chiral auxiliary.
[reaction: see text] The new macrocycle 9 (>70% yield from hydroxythiol 10) was treated with several nucleophilic reagents (RMgX, RLi, and LiAlH4) affording carbinols 12a-j (80-96% yield, >99:1 dr). Oxidative hydrolysis of 12a,c,e, followed by LiAlH4 reduction of the resulting mixture, gave 16a,c,e in >95% ee,16c being a key precursor for the preparation of fungicide 17. The absolute configuration of 9 and 12j (Nu = H) was established by single-crystal X-ray diffraction analyses and chemical correlation.
Vargas-Díaz
M Elena
ME
Departamento de Química OrgAnica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. de Carpio y Plan de Ayala, México, D.F., 11340 Mexico.
Joseph-Nathan
Pedro
P
Tamariz
Joaquín
J
Zepeda
L Gerardo
LG