Chemical Forums

Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: Fzang on March 01, 2011, 06:51:29 AM

Title: Cyclic acetals derived from aldehydes.
Post by: Fzang on March 01, 2011, 06:51:29 AM

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fcl.ly%2F4uGE%2FScreen_shot_2011-03-01_at_12.45.01_PM.png&hash=e81bad330d5da0b2ff547ace70821a1ad82c6ad0)

Which of these are derived from 4-hydroxyheptanal? I've tried but I really can't draw any 5-membered rings that look like any of the above (while I know some of them are not even 7-carbon). What am I not understanding?

Title: Re: Cyclic acetals derived from aldehydes.
Post by: sjb on March 01, 2011, 10:23:43 AM

Quote from: Fzang on March 01, 2011, 06:51:29 AM

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fcl.ly%2F4uGE%2FScreen_shot_2011-03-01_at_12.45.01_PM.png&hash=e81bad330d5da0b2ff547ace70821a1ad82c6ad0)

Which of these are derived from 4-hydroxyheptanal? I've tried but I really can't draw any 5-membered rings that look like any of the above (while I know some of them are not even 7-carbon). What am I not understanding?

How do you form a regular hemi-acetal from, say butanal and ethanol?

Title: Re: Cyclic acetals derived from aldehydes.
Post by: Fzang on March 01, 2011, 02:42:53 PM

(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fcl.ly%2F4wAg%2FScreen_shot_2011-03-01_at_8.41.24_PM.png&hash=6fcfabf2fe73aa602fb3121c29aff21eb94c0f3b)

Wow, I'm sorry. I guess I might've looked a completely wrong place, i.e. drawing a different angle than the answer shows. I really have no explanation why I failed that so miserably.  :-X