Organic Question...

[scottyhoop]

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I was thinking about something today and it's been a while since I took organic, so any of you that know/remember help me out. Why would 2 epimers (glucose and mannose) have 2 different boiling points and melting points? Thanks!!
Scott

 

[link2swim06]

I was thinking about something today and it's been a while since I took organic, so any of you that know/remember help me out. Why would 2 epimers (glucose and mannose) have 2 different boiling points and melting points? Thanks!!
Scott

A epimer is a stereoisomer with one different configuration at one stereogenic center. Do you remember that molecules stability is directly related to the axial vs. equatorial position. The molecule of glucose has a axial hydroxyl group at the C2 position and mannose has a equatorial hydroxyl group at the C2 position. Therefore mannose is less stable and therefore should have a lower BP.

 

[scottyhoop]

Sweet...thats kinda what I remembered, but you explained it very well. Thanks for the confirmation!!
Scott