st scnsitivit?. and specicactions with 2- and 3deoxyaltlos~~s, and n i t h thcir G - d e o q ~ deriv:itivcLs. I n distinguishing thew sugai'ij from each other it \$as of value to o h s c v e t,hi. si'rn!-ctl chromxtopnms ring th(3 ric3riorl of heating iiie therii again 2: hours For exampic., mycarosc m r l c1.iclinose gave a transient purpli. fl:, rc' during h t t i n g , wjimeas D-digitoxosi~ did rii:i : the 3-drosy- and 3,cishowed a very characteristic chitrig(%in color from gray-brown to i m r l ~ ! ~ ~ - gnirhin r ~ y 24 hours of heating. .4lthough the scnsit'ivity of the latter reaction could not be measured dircctly h!>s~.ausethe pure sugars were not available, it' is very probably less th:in 10 y, because the intensity of rcxction was not very different from that givcm by the very sensitive ammoniacal silvor nitrate spray. The :$.mitivity of the test for 6deoxyhcxoscs was relatively low, ranging from 50 y for r,-rhamnose to >lo0 y -gliicose. All but one of these sugars produced a rapidly fading orange-red :,r orange-gray color; 6deoxy-1,-idose gave a stable gray-blue. I n view of the rapid fading it was necessary to inspect the chromatograms frequently during the heating period and
to avoid ovwhc:tting. Even with these irrecautions: reproducibility with respect to color and scnsitivitj. was not good. The rapidly fading orange color appeared to be spccific for the 6-dcoxyhcyosps, as it \vats not produecd h y 6deoxyhesitols, 2,6- anti 3,6-ditier~syhexoses, or the p:ircnt :ildoses. Ifon-c w r , thc7 weak rcactioii of :L single 7deoxyheptose raises the possibility that stronger reactions might be givm by other sugars of this class. Sel-crd 0rncthyl ethers of rhamnose reactcd in the same way as rA-rhamnosc, but it :rppcars that certain 0-methylatc'il 6deoxyhexoses may give colors diffcwnt from that given by the parent sugar; this point has not bccn adcquntcly investigatcd. ACKNOWLEDGMENT
Thi. authors acknon ledge gcnuous gifts of sugars, sugar derivatives, and pols saccharidcs from M. J. Crunipton, D. A . L. Davies, ,4.B. Fostcr, E. L. Hirst, I€. S. Isbell, P. P. Regna, T. Reichstcin, S . I
