Banca de QUALIFICAÇÃO: ANALÚ CAMPOS REIS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ANALÚ CAMPOS REIS
DATE: 20/12/2021
TIME: 08:00
LOCAL: google meet
TITLE:

 

 

Identification and synthesis of semiochemicals involved in the communication of Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae) and Anthonomus grandis Boheman (Coleoptera: Curculionidae)

KEY WORDS:

 semiochemicals, pheromone synthesis, pest control

PAGES: 65
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Química dos Produtos Naturais
SUMMARY:

Agribusiness in Brazil represents one of the main segments of the economy, among the main economically relevant crops are cotton and arecaceas. Insect pests are a limiting factor for the cultivation of arecaceas and cotton, causing a reduction in productivity. Anthonomus grandis Boheman (Coleoptera: Curculionidae), known as the cotton boll weevil, in its larval stage, develops inside the flower buds, thus causing a reduction in productivity. Atheloca subrufella (Hulst) (Lepidoptera: Phycitidae), known as coconut moth, causes injury to the plant when in the larva stage, it feeds on the fruit's mesocarp, preventing the flow of sap causing it to drop. premature, thus decreasing coconut yield. The use of sprays with insecticides to control these pests is not efficient, as they lodge mainly inside the plant/fruit and the insecticides are not able to reach them. In this context, semiochemicals are presented as an efficient and sustainable control method. Thus, this research aimed to synthesize the semiochemicals responsible for the attractiveness of these insects. A. grandis already has its pheromone mixture identified, formed by four compounds: (+)-cis-2-isopropenyl-1-methyl-cyclobutane-ethanol (Grandisol); (Z)-3,3-dimethylcyclohexylidene-ethanol (Grandlure II); (E)-3,3-dimethylcyclohexylidene-acetaldehyde (Grandlure III); and (Z)-3,3-dimethylcyclohexylidene-acetaldehyde (Grandlure IV). Grandlures II, III and IV were obtained by a single synthetic route, in just three steps, through an α,β-unsaturated intermediate, the acetate of [(E,Z)-ethyl-2-(3,3- dimethylcyclohexylidene)], formed by the Horner-Wadsworth-Emmons Reaction. . The alcohol was obtained by reduction with lithium aluminum hydride and the aldehydes by oxidation of the alcohol with PCC, with an overall yield of 82,4 %. 13-Methyl-heptacosane was indicated as an active component in cuticular extracts of female A. subrufella. For the synthesis of this molecule, a route containing seven steps was proposed, using Grignard reactions as a strategy for the elongation of the carbon chain and insertion of the branch at position 13, obtaining an overall yield of 4, 26 %. The proposed routes proved to be effective for obtaining the five target molecules. The next steps consist of confirming the identity of the compound 13-methyl-heptacosane and synthesis of the compound (+)-cis-2-isopropenyl-1-methyl-cyclobutane-ethanol.

 

BANKING MEMBERS:
Presidente - 1119939 - ANTONIO EUZEBIO GOULART SANTANA
Interna - 1247925 - ANIELLE CHRISTINE ALMEIDA SILVA
Interna - 426640 - FABIANE CAXICO DE ABREU GALDINO
Externo à Instituição - SÍLVIO DO DESTERRO CUNHA - UFBA