Gulose pyranose form

Reeves has suggested that the spontaneous formation of 1,6-anhydro derivatives of idopyianose and altropyranose may be due to the conformational behavior of the aldoses his instability factors show that /3-Didose and /3-D-altrose will exist partly in the conformations favorable for closure of the 1,6-anhydro ring. This reasoning could lead to the further conclusions that D-talose, but probably not n-gulose, should fairly readily afford a 1,6-arihydro derivative of the pyranose form. 

Gulofuranosyl bromide p-D-/orm 2,3 5,6-Di-0-(ethylboranediyl), G-582 Gulose a-L-Pyranose-/orm, G-587 Gulose D-form, G-587 Gulose L-form, G-587... 

Some 40 years ago Isbell (16) observed complex formation between calcium ions and a sugar which possesses the ax-eq-ax sequence—i.e., a-D-gulopyranose. He observed that an equilibrated solution of D-gulose, CaCl2, underwent further mutarotation on dilution with water and he correctly interpreted the phenomenon by postulating that a-D-gulo-pyranose (10), but not -D-gulopyranose, forms a complex with calcium... 

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