Sintese de produtos naturais oticamente ativos

AUTOR(ES)
DATA DE PUBLICAÇÃO

1993

RESUMO

This work describes the synthesis of a mono oxygeneted sesquiterpene, the (Z)-(1S,2R,4S}-(-)-1,2 epoxy-1-methyl-4 (1 ,5 -dimethyl-1 ,4 -hexadienyl)-cyclohexane 45, major component of sex pheromone of the green stink bug Nezara viridula L. (Heteroptera, Pentatomidae). The insect Nezara viridula L., known in Brasil as "maria fedida", is considered one of the principal pest of soybean, cotton, citrus, cereal and vegetable cultures, and is widespread throughout tropical and neotropical regions of the world. The synthesis of epoxybisabolene 45 was proposed considering a convergent route, where the coupling of the cyclic portion, the epoxy ketone 61 the acyclic portion, the phosphine oxide 68, was accomplished through of a Horner-wittig reaction, allowing the double bond geometry control. The cyclic portion, the epoxy ketone 61, was prepared following two synthetic sequences from chirals precursors, the (S)-(-) perillyl alcohol 53 (four steps, 46% overall yield) and (S)-(-)-limonene (two steps, 33% overall yield). The acyclic portion (phosphine oxide 68) was also prepared following a convergent route, from isoprene 65 and triphenylphosphine in 81% overall yield (four steps). The Horner-Wittig reaction between 61 and 68 allowed to obtain besides the erytro b hydroxy phosphine oxide 77, precursor of the (Z)-(-) epoxybisabolene 45, the (E)-(-) epoxybisabolene 78 in a pure form. The (Z)-(-) epoxybisabolene 45 was then obtained with an overall yield of 16% from (S)-(-) perillyl alcohol (ten steps) or 11% (overall yield) from (S)-(-)-limonene in eight steps.

ASSUNTO(S)

pesticidas sesquiterpenos

ACESSO AO ARTIGO

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