Camphorsulfonamide-Shielded, Asymmetric 1,4-Additions and Enolate Alkylations; Synthesis of a Southern Corn Rootworm Pheromone. Preliminary Communication
作者:Wolfgang Oppolzer、Philip Dudfield、Thomas Stevenson、Thierry Godel
DOI:10.1002/hlca.19850680126
日期:1985.2.13
Cα and Cβ of carboxylates could be conveniently achieved. Thus, conjugated additions of RCu to enoates (12) furnished, after saponification, β-substituted carboxylic acids 3 in 94–98% e.e. Similarly, propionates 12 yielded after deprotonation, enolate alkylation, and reductive ester cleavage the (R)-alcohols 15 in 78–98% e.e. The acid (+)-3e was converted to the pheromone (–)-11.
使用容易获得10磺酰氨基isoborneols作为再生,手性助剂,中C高度选择面孔C-C键的形成α和C β的羧酸盐可以方便地实现。因此,在皂化后,将RCu共轭添加到烯酸酯(1 2)中,可得到94-98%ee中的β-取代的羧酸3。类似地,在去质子化,烯酸酯化烷基化和还原性酯裂解(R)醇后生成丙酸酯12。15在78–98%ee中将酸(+)- 3e转换为信息素(-)- 11。