Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Zalzul on May 01, 2018, 03:12:39 PM
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In performing ozonolysis on , specifically with the procedure of (step 1) O3 @ -78 °C and (step 2) (CH3)2S in water, I came up with 3 different products:
, , and
Given the subsequent reaction (reduction with sodium borohydride in methanol followed by acidic workup), I was confused as to the point of trying to generate multiple products: methanol, glycolic acid, and acetic acid. According to the book, the only product to consider is the middle one: , with the end product (following the aforementioned reduction and subsequent treatment with hot sulfuric acid) being prop-2-enoic acid. This acid then goes on to be the dienophile in a Diels-Alder reaction.
In reflecting on this, I cannot reason as to why one would discount the methanol and acetic acid, for fear of unwanted ether and/or ester products given the hot and acidic environment once the sulfuric acid is added.
Can someone clarify for me as to why I needn't consider either formaldehyde or acetic acid in the ozonolysis of pent-1-en-4-yne? Thanks in advance.
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I think the trick is to stop it from letting the reaction go all the way to completion. It should react with the triple bond first and more often than not.
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Ah, I see; perhaps then that's what meant by the cold temperature during the ozonolysis step.
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That's what caught my eye as well.