Conversion of other aldohexose sugars

1 open chain structure of D-iodose

  D-iodose

2 Rotated 90° clockwise direction

  

3 Connect C1 carbon with oxygen of C5 carbon by putting C1 OH downward(alpha form)

4 Stretched the structure in a way as bath tub bay making base as 2,3 carbon

5 Assign the H and OH group to each carbon as same (if H is above then put in upward , if H is below then put in downward, similarly for OH) as above structure

6 The completed structure given below is the HAWORTH STRUCTURE of D-iodose

Conversion of Haworth to chair form

1 Stretch C1 carbon downward and C4 carbon upward direction

2 Now assign H and OH groups to each carbon as same way in above Haworth projection 

This is the final chair form of  alpha D-iodose

Now we can convert any following aldohexose sugar to their chair form by the above simple steps.