1. Fischer has devise a projection formula to reláte the two enantiomeric forms. Base on this, carbohydrates are named as D or L.
2. + and – sign indicates the dextro rotatory and levo rotatory respectively.
3. Dextre rotatory compound rotate the plane of plane polarised light in clockwise direction while the levo rotatory compounds rotate in anticlockwise direction.
4. Dextro rotatory compounds are represented as D (+) or L (+) and the levo rotatiory compounds as D (-) or L (-).
