We report the syn-selective Michael addition of a series of substituted primary and secondary nitromethane derivatives 4a-g to chiral enoates (Z)-2a and (E)-2a in the presence of TBAF‚3H 2 O or DBU. Regardless of the base employed, adducts syn-5a-g were obtained in good de (80-100%) from the reactions of 4a-g with (Z)-2a. However, in the addition to (E)-2a, the syn-diastereoselectivities depended on the structure of the nucleophile (80-90% de for nitromethane (4a), 80% de for phenylnitromethane (4g), 50 and 34% de for the primary nitromethane derivatives 4b and 4d, and 0 and 6% de for the secondary nitromethane derivatives 4c and 4f). A mixture of epimers (2:1/1:1) was obtained at the chiral center bearing the nitro group in 5b and 5d-g. The syn/anti ratio C-3,C-4 is kinetically controlled, while the epimeric ratio at the CNO 2 chiral center (C-1′) seems to be thermodynamically controlled. Adducts 5a,b,c,g were transformed into the respective cis-,γ-disubstituted γ-butyrolactones 6a, 7, 9a, and 9c. A mechanistic rationale to explain the observed diastereoselectivities is proposed.
RESUMO -Objetivou-se analisar a influência da adição de níveis crescentes de óleo de soja e canola sobre os índices de desempenho e qualidade interna e externa dos ovos de poedeiras comerciais semipesadas da linhagem Bovans Goldline durante cinco períodos de 28 dias. Foram utilizadas 280 aves com 18 semanas de idade, em um delineamento inteiramente casualizado, com sete tratamentos em um esquema fatorial 2 × 3 + 1 (dois tipos de óleo e três níveis de óleo mais um testemunha adicional) com cinco repetições e oito aves por unidade experimental. Os níveis de óleo de soja e de canola não alteraram o consumo de ração, os pesos dos ovos, de albúmen, de gema e de casca, as porcentagens de albúmen, de gema e de casca e a gravidade específica dos ovos. Houve influência significativa da interação tipo × nível de óleo sobre a produção de ovos e a conversão por massa e por dúzia de ovos. Com o aumento do nível de óleo de soja, os resultados obtidos para estas variáveis melhoraram, entretanto, a conversão por massa de ovo piorou com o aumento dos níveis de óleo de canola. A adição de óleo de soja promoveu desempenho melhor que o obtido com óleo de canola.Palavras-chave: aves de postura, óleo de canola, óleo de soja, produção de ovos
Performance and eggs quality in laying hens fed diets with soybean and canola oilsABSTRACT -The objective of this study was to evaluate the influence of soybean and canola oil added in crescent levels on production performance indexes and internal and external egg quality of brown commercial layers of the strain Bovans Goldline during five periods of 28 days. Two hundred and eighty hens with 18 weeks old were distributed in a completely randomized design, with seven diets in a 2 × 3 + 1 factorial arrangement (oil type and oil level, and an additional control), with 5 replicates of 8 hens per experimental unit. The soybean and canola oil levels did not affect the feed consumption; egg, albumen, yolk and shell weights; albumen, yolk and shell percentages, neither the specific gravity. There was an interaction between type and oils levels on egg production and mass conversion and per egg dozen.Better results for those characteristics were obtained as soybean oil increased. However, the egg mass conversion was negatively influenced by increase of canola oil. The addition of soybean oil promoted better performance as compared to canola oil.
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