A novel and efficient method is proposed for the synthetic preparation of a long-chain alkynyl compound in a one-pot reaction without isolating the intermediate from the reaction mixture. The inventive method comprises the steps of: (a) a Grignard coupling reaction of an .omega.-halogeno-1-alkynyl magnesium halide compound of the general formula X.sup.1 MgC.tbd.C(CH.sub.2).sub.n X.sup.2, in which X.sup.1 is a halogen atom, X.sup.2 is an atom of Br or I and n is 3 to 10, and a Grignard reagent of the general formula RMgX.sup.1, in which R is a group selected from the class consisting of alkyl groups, alkenyl groups, alkynyl groups, alkapolyenyl groups, aryl groups and hydrocarbon groups having protected hydroxy group to give an intermediate compound of the general formula X.sup.1 MgC.tbd.C(CH.sub.2).sub.n R; (b) subjecting the intermediate compound to a reaction with a reactant selected from the class consisting of C.sub.2 -synthons, C.sub.1 -synthons and chlorosilane compounds having reactivity with the intermediate compound at the X.sup.1 Mg-terminal; and (c) hydrolyzing the reaction product obtained in step (b).
A Convergent and Highly Efficient Synthesis of (<i>E,Z</i>)-2,13-Octadecadienyl Acetate and (<i>E,Z</i>)-3,13-Octadecadienyl Acetate, Components of the Sex Pheromone of the Leopard Moth <i>Zeuzera pyrina</i>, through Sulfones
作者:Anna Capdevila、Attaluri R. Prasad、Carmen Quero、Inés Petschen、Maria P. Bosch、Angel Guerrero
DOI:10.1021/ol990114j
日期:1999.9.1
[GRAPHICS]A new, convergent synthesis of (E,Z)-2,13 octadecadienyl acetate (1) and (E,Z) 3,13 octadecadienyl acetate (2), the two key components of the leopard moth Zeuzera pyrina, from 2 chloromethyltetrahydrofuran in good overall yields and stereomeric purity is reported. The synthesis of both components utilizes the common intermediate sulfone 12 as a convenient building block to be coupled with iodoacetylenic derivatives 9 or 17 in the key step.