Enzymatic Desymmetrization of meso-2,6-Dimethyl-1,7-heptanediol. Enantioselective Formal Synthesis of the Vitamin E Side Chain and the Insect Pheromone Tribolure
摘要:
The chiral syn-1,5-dimethylalkyl subunit is found in many natural products with significant biological activities. Enzymatic esterification of meso-2,6-dimethyl-1,7-heptanediol with isopropenyl acetate in the presence of Pseudomonas cepacia lipase in organic medium provided the chiral nonracemic monoester in high enantiomeric excess (ee = 95%). This chiral building block was used in the formal syntheses of vitamin E side chain and the insect pheromone tribolure.
Synthesis of All the Stereoisomers of 13,17-Dimethyl-1-tritriacontene and 13,17-Dimethyl-1-pentatriacontene, the Contact Sex Pheromone Components of the Female Tsetse Fly, Glossina austeni
All of the stereoisomers of 13,17-dimethyl-1-tritriacontene (1) and 13,17-dimethyl-1-pentatriacontene (2), the contact sexpheromonecomponents of the female tsetse fly (Glossina austeni), were synthesized starting from the enantiomers of the protected syn- and anti-2,6-dimethylheptane-1,7-diol (3), which were prepared from the enantiomers of methyl 3-hydroxy-2-methylpropanoate (4) and methyl phenyl