Furanoses and Ketoses

[a_zed24]

Hello there,
I was wondering about the fact that fructose's chain rings up as a furanose...is there any correlation between ketose sugars and furanose rings in general? In other words, do all ketoses form a furanose ring?
Thanks!

[chenbeier]

No, Ketose means only it has a Keto group  =CO in the chain or ring. Aldose cugar has an Aldehydgroup. "Fructose  is a five ring molecule as basic  furan. Furanose is a collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle furan, but the furanose ring does not have double bonds." (from https://en.wikipedia.org/wiki/Furanose)

[hypervalent_iodine]

2 hours ago, chenbeier said:

No, Ketose means only it has a Keto group  =CO in the chain or ring. Aldose cugar has an Aldehydgroup. Fructose  is a five ring molecule as basic  furan. Furanose is a collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle furan, but the furanose ring does not have double bonds.

 

!

Moderator Note

If you are going to copy-paste from another website, please make it clear and include a citation. I have edited your post to include one. 

 

[chenbeier]

13 minutes ago, hypervalent_iodine said:

 

!

Moderator Note

If you are going to copy-paste from another website, please make it clear and include a citation. I have edited your post to include one. 

 

Sorry I thought wiki is a webside where I can copy.  English is not my mother language. So next time I post only a link where the people can read or is this also forbidden in this forum.

[hypervalent_iodine]

Just now, chenbeier said:

Sorry I thought wiki is a webside where I can copy.  English is not my mother language. So next time I post only a link where the people can read or is this also forbidden in this forum.

!

Moderator Note

It is fine to quote from another website if there is something specific you wish to point out, just make sure you also post a link. 

 

[StringJunky]

15 minutes ago, chenbeier said:

Sorry I thought wiki is a webside where I can copy.  English is not my mother language. So next time I post only a link where the people can read or is this also forbidden in this forum.

The best way to do it I think is like this: Copy text > Hit the quote button (speech mark ") in the bar above in the text box > Paste text in > Copy url from that page, make a space and paste at the bottom. Double tap your cursor out of the box at the end of the line or try clicking outside the box to escape... can be one or the other.

Quote

A furanose is a collective term for carbohydrates that have a chemical structure that includes a five-membered ring system consisting of four carbon atoms and one oxygen atom. The name derives from its similarity to the oxygen heterocycle furan, but the furanose ring does not have double bonds. [1]

https://en.wikipedia.org/wiki/Furanose

Also, don't quote a whole page if there's a lot; just post the important bits and the link can be followed if someone is interested enough.

Edited October 12, 2018 by StringJunky

[BabcockHall]

Ribose is a furanose that is an aldose; therefore, one has to be very careful about making generalizations.  Think about sedoheptulose.