mistake???? dat destroyer ochem

[beauml]

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2010 dat destroyer pg 110.

cyclopentanone is treated with ethanol/H+.
product is 1-hydroxy-1-ethoxycyclopentane. (i dont know if this naming is right....)

and it saids it is hemi-acetal... why? C1 is occupied by 4 bonds, but none has H attached to it.

shouldnt it be hemi-ketal?

it also saids, if the cyclopentanone is treated with 2 ethanol. it become acetal......
so confused....

last minute studying with Kaplan and Destroyer freaks me out... especially the practice test 3 of kaplan is full of mistake questions and answers.

 

[njdoc327]

its correct. look up the picture of a hemiacetal. with one mole of ethanol, the product will be a hemiacetal and with 2 moles of ethanol the product will be an acetal.

 

[mario0923]

its correct. look up the picture of a hemiacetal. with one mole of ethanol, the product will be a hemiacetal and with 2 moles of ethanol the product will be an acetal.

I don't think acetal is correct

cyclopentanone is a ketone and a ketone cannot become an hemi-acetal/acetal
since it has both R groups attached

I think 1 ethanol attacks the carbonyl carbon of the ketone and the carbonyl carbon has now 2 R-groups and one hydroxy and one OCH2CH3 so this is a hemi-ketal (Nucleophilic addition)

and then if you add one more ethanol hydroxy group leaves by the attack of ethanol (Sn1) and now you have 2 R groups and two OCH2CH3 groups attached to the carbon that was carbonyl. so now it is a ketal