II. CHEMISTRY 



189 



this method invohcd tlie preparation of the somewhat inaccessible starting 

 material L-xylosone or L-lyxosone (XII). Two pathways, involving reactions 

 XV to XII (procedure a) and XXIV to XII (procedure h), devised for this 

 purpose are formulated below. 



Procedure a^* 



CHO 



I 

 H— C— OH 



HO-Cf-H ^,,,,, 



HO— C— H H=so. 

 1 

 H— C— OH 

 I 

 CH2OH 



XV 

 D-Galactose 



H 



H-C^ 



.0— C— H 

 ^0— C— H 



K.MnO, 



*i; 



I 



CO—" 



I 

 CH20H 



XVI 

 Diisopiopylidene- 

 D-galactose 



H— C^ 



H-C^ ^ 



I 

 ,0— C— H 



.r 1 



^0— C— H 

 I 

 CO—" 



II2S0, 



CHO 



I 

 H— C— OH 

 I 

 HO— C— 



I 

 COOH 



XVII 



Diisopropylidcne- 

 D-galacturonic acid 



?-" 



HO— C— H 

 I 

 H— C— OH 

 I 

 COOH 



XVIII 



D-Galacturonic 

 acid 



NaHg 



CHO 

 I 

 H— C— OH 



I 

 H— C— OH 

 I 

 HO— C— H 

 I 

 CHjOH 



XXII 

 L-Lyxose 



NaOCl 



CONHj 



HO— C— H 



I 

 H— C— OH 



I 

 H— C— OH 

 I 

 HO-C— H 

 I 

 CH5OH 



XXI 



NH3 



CO — 



I 



HO— C— H 

 I 

 H— C— OH 

 I 



H— CO 



I 

 HO— C— H 

 I 

 CHjOH 



XX 



L-Galactono- 

 gamma-lactone 



- H,o 



COOH 



I 

 HO— C— H 



I 

 H— C— OH 



I 

 H— C— OH 



I 

 HO— C— H 



I 



CH2OH 



XIX 



L-Galactonic acid 



CH=N— NH— CeHs 

 I 

 C=N— NH— CeHs 



H— C— OH 

 I 

 HO— C— H 

 I 

 CH2OH 



XXIII 



L-Lyxosazone 

 or L-xylosazone 



CsHsCHO 



CHO 

 I 

 CO 



I 



H— C— OH 

 I 

 HO— C— H 

 I 

 CH.OH 



XII 



L-Lyxosone 

 or L-xylosonc 



Ip = C(Me)2 



" T. Reichstein, A. Griissner, and R. Oppenauer, Helv. Chiin. Acta 16, 561 (1938). 

 " R. G. Ault, D. K. Baird, H. C. Carrington, W. N. Haworth, R. W. Herbert, E. L. 



Hirst, E. G. V. Percival, F. Smith, and M. Stacey, J. Chem. Soc. 1933, 1419. 

 " D. K. Baird, W. X. Haworth, R. W. Herbert, E. L. Hirst, F. Smith, and M. Stacey, 



J. Chem. Soc. 1934, 62. 



