Question

The electronic nature of carbonyls and carboxylates (and their derivatives) rests predominantly on the disparity in electronegativity values of the two nuclei of the functional group. For the moment, let's look at the "all-carbon" analog: the alkene. Provide the major resonance contributor(s) for the following alkene: If there exists any propensity for electrophilic or nucleophilic chemistry on either vinyl carbon, indicate so by circling the appropriate carbon and labeling it "nucleophile" or "electrophile" in the figure above. c. For the simple aldehyde acetaldehyde, provide any major resonance structures in the space below. Acetaldehyde's structure is provided to you. As in part b above, indicate any nuclei that should function as a nucleophile or electrophile by circling it and labeling it appropriately. In the carboxylate derivative, the ester shown below, provide any major resonance contributors, as in part a and part b above. As in part b above, indicate any nuclei that will function as potential nucleophile or electrophile by circling the nuclei and indicating their reactivity. For the following sequence of structures, arrange the corresponding letters along the axis in increasing reactivity to nucleophiles.

Answer 1

Answer a &b potential nucleop mle potential electrophile R3 R3 Resonance contributors of allæne If size ofalkyl g ncreases in below order R R2R3 R4 then resorating structure (I) exist Answer c & d potential nucleophile H3C potential elec trop hile Resonance contib utors of acetaldehyde Answer e &f potential Imcleop hile H3C OCH3 H3C OCH3 potential electrop hile Resonance coniib utors of methyl acetate Answer g Dedreasing order of reactivity towards nucleophile will be as follows because the electrophilicity of the carbonyl carbon decreases in the same order CI OCH3 NH2 Acetyl chloride most reactive bcause Cl is a good leaving group which makes carbonyl carbon most. electrophilic Acetamide least reactive bcause NH2 donates it's lone pair of eledtron which makes carbonyl carbon1east electrophilic Acetaklehyde Methyl acetate