Pruebas quimicas para identificacion de aldehidos y cetonas

Química Orgánica 3 Aldehídos y Cetonas

Dra. Angélica Berenice Aguilar Guadarrama

Vanillin and cinnamaldehyde are examples of naturally occurring aldehydes. A whiff of vanilla extract will allow you to appreciate the pungent odor of vanilla. The ketones carvone and camphor are responsible for the characteristic sweet odors of spearmint leaves, caraway seeds, and the camphor tree.

Two ketones that are of biological importance illustrate how a small difference in structure can be responsible for a large difference in biological activity: Progesterone is a female sex hormone synthesized primarily in the ovaries, whereas testosterone is a male sex hormone synthesized primarily in the testes.

2-­‐fenilbutanodial  

Oxidation of aldehydes

reagent

(Tollen’s) Fehling’s or Benedict’s Oxidation of ketones.

Addition of Water

Friedel–Crafts Acylation of Benzene

mechanism for Friedel–Crafts acylation

Oxidative Cleavage of Alkenes

resonance contributors of ozone mechanism for ozonide formation

Escriba la estructura del producto de la reacción de bromuro de propilmagnesio con cada uno de los siguientes. Asuma que las reacciones son finalizadas por la adición de acido acuoso diluido. a)  b)  c)  d) 

Formaldehido Benzaldehido Ciclohexanona 2.butanona

Muestre como pueden ser preparados los siguientes compuestos, usando etino como uno de los materiales iníciales. a)  1-pentin-3-ol b)  1-fenil-2-butin-1-ol c)  2-metil-3-hexin-2ol

Reacción de aldehídos y cetonas con cianuros

Como pueden ser preparados los siguientes compuestos, iniciando con un compuesto carbonílico con un carbono menos que el producto deseado a)  HOCH2CH2NH2

Reacción de aldehídos y cetonas con hidruros

Reac1vos  selec1vos  para  la  reducción  de  grupos  carbonilo    

Reacción de aldehídos y cetonas con nucleofilos de Nitrógeno

Reducción de Wolff Kishner

Reación de Wittig

Reacción de aldehídos y cetonas con nucleofilos de Oxígeno

Estereoquímica de las reacciones de adición nucleofilica: Caras Re y Si de Oxígeno

SYNTHESIZING ORGANIC COMPOUNDS Organic chemists synthesize compounds for many reasons: to study their properties or to answer a variety of chemical questions, or because they have unusual shapes or other unusual structural features or useful properties. One reason chemists synthesize natural products is to provide us with greater supplies of these compounds than nature can produce. For example, Taxol —a compound that has been successful in treating ovarian and breast cancer—is extracted from the bark of Taxus, the yew tree found in the Pacific Northwest. The supply of natural Taxol is limited because yew trees are uncommon and grow very slowly and stripping the bark kills the tree. The bark of one tree provides only one dose of the drug. In addition, Taxus forests serve as habitats for the spotted owl, an endangered species, so harvesting the trees would accelerate the owl’s demise. Once chemists were successful in determining the structure of Taxol, efforts could be undertaken to synthesize it in order to make it more widely available as an anticancer drug. Several syntheses have been successful. Once a compound has been synthesized, chemists can study its properties to learn how it works; then they can design and synthesize safer or more potent analogs. For example, chemists have found that the anticancer activity of Taxol is substantially reduced if its four ester groups are hydrolyzed. This gives one small clue as to how the molecule functions.

Adición nucleofilica a aldehídos y cetonas α, β insaturados

CANCER CHEMOTHERAPY Two compounds—vernolepin and helinalin—owe their effectiveness as anticancer drugs to conjugate addition reactions. Cancer cells are cells that have lost their ability to control their growth; therefore, they proliferate rapidly. DNA polymerase is an enzyme that a cell needs to make a copy of its DNA for a new cell. DNA polymerse has an SH group and each of these drugs has two α, β-unsaturated carbonyl groups. Irreversible conjugate addition of the enzyme to an α, β–unsaturated carbonyl group inactivates the enzyme.