The synthesis of the isomeric components of San Jose scale pheromone - An illustration of a stereospecific synthesis of trisubstituted alkenes
The three isomeric components of the San Jose scale pheromone, 5-7, have been synthesized from a common β-keto ester intermediate. A study of the alkylation of the dianion of methyl acetoacetate with a series of alkylating agents with the same carbon skeleton has been carried out. The trisubstituted alkenes in 5 and 6 have been synthesized stereospecifically via a copper-catalyzed coupling of a methyl Grignard reagent with the E or Z enol phosphate from the alkylated β-keto ester. In the case of the Z enol derivative, the coupling reaction was carried out on the diethyl- and diphenylphosphates, and the enol triflate. The diethyl enol phosphate gave the highest stereoselectivity. The synthetic pheromones were attractive to San Jose scale in the field.
A compound of formula (I) useful for the treatment or prevention of hepatitis C viral infection, (Formula (I)) wherein: X1 and X2 are each independently CRB or N; RB is H, (C1-6)alkyl, (C1-6/sub
-
Page/Page column 44
(2013/03/26)
More Articles about upstream products of 90545-36-1