The ring structure of mannose. The optical rotation of 4-glucosido-alpha-mannose

H.S. Isbell
1930 Bureau of Standards Journal of Research  
A comparison of the rotation of two pairs of sugars, which can not form a 1 4 ring shows that one pair gives an epimeric difference in rotation, which agrees with the value obtained from a-d-mannose ( + 30) and the normal form of glucot? while the other pair gives a value which agrees with that obtained from^E SZJnose (-17) and the normal form of glucose. These results may be interpret ,.,1 as indicating that 4-glucosido-a-mannose and 4-galactosido-/3-mannose have structures similar to a-and
more » ... mannose, respectively. However, regardless of the particular interpretation, the different values show that a decision between the rival ring classifications can not be reached from a comparison of the rotations of cellobiose and glucosido-mannose. CONTENTS Page 1, 5 ring as shown by methylation studies. In a recent publicatioi] Hudson 3 states that the methylation data upon, which his previous assignments were based are invalid. He now assigns the 1, 5 ring to the methyl glucosides and the 1, 4 ring to a-methyl-f/-mannoside. It is claimed that the whole system of ring structures, as developed 1
doi:10.6028/jres.005.071 fatcat:yi3nah72q5bjnd4tsk2rvkweqi