Synthesis of 4‐Octuloses. Part 6. 4‐Octulose Derivatives, Prepared from L‐Sorbose, as Key Intermediates in the Stereoselective Synthesis of C‐Glycoside and Polyhydroxyindolizidine Analogues.
Reactions of 1 and 12 with p-toluenesulfonyl chloride in pyridine gave the corresponding 1-O-p-toluenesulfonyl derivatives 2 and 13 in yields of 91% and 60%, respectively. Compound 12 was also transformed into 14 by treatment with I2/ Ph3P/imidazole in anhydrous dichloromethane. Treatment of compounds 12 and 13/14 with NaN3 in DMF furnished the respective 1-azido-1-deoxy derivatives 3 and 15, which were then deacetonated to give the free 4-octuloses 4 and 16. These were subsequently hydrogenated in the presence of 10% Pd/C to afford the expected polyhydroxylated branched-chain pyrrolidines 5 and 17. Attempted OH R
4‐Octulose Derivatives, Prepared from L‐Sorbose, as Key Intermediates in the Stereoselective Synthesis of C‐Glycoside and Polyhydroxyindolizidine Analogues
Reactions of 1 and 12 with p-toluenesulfonyl chloride in pyridine gave the corresponding 1-O-p-toluenesulfonyl derivatives 2 and 13 in yields of 91% and 60%, respectively. Compound 12 was also transformed into 14 by treatment with I2/Ph3P/imidazole in anhydrous dichloromethane. Treatment of compounds 12 and 13/14 with NaN3 in DMF furnished the respective 1-azido-1-deoxy derivatives 3 and 15, which were then deacetonated to give the free 4-octuloses 4 and 16. These were subsequently hydrogenated in the presence of 10% Pd/C to afford the expected polyhydroxylated branched-chain pyrrolidines 5 and 17. Attempted OH OMes transformation at C-8 in the N−Cbz-protected pyrrolidines 7 and 19 was unsuccessful and an internal anhydration process took place to yield the corresponding C-glycoside-like furanoses 9 and 20. On the other hand, 23 was transformed into the D-ribo analogue 25 through reduction of the intermediate 4,6-diulose 24. Finally, deprotection of 25 in acid medium to give the free 4-ulose 26, followed by hydrogenation of the latter in the presence of 10% Pd/C in methanol, allowed the preparation of (6S,7S,8S,8aS)-6,7,8-trihydroxy-8a-methoxyindolizidin-3-one (27).
Studies on the composition, quality and processing of triticale. Part II. Mineral composition of grain and flour.
Mineral composition of grain and flour in 14 promising triticale strains from India are reported. The mean values for whole grain, i.e. Ca (0.47 mg/g), P (2.70 mg/g), K 4.60 mg/g, Na (352 micrograms/g), Zn (41.6 micrograms/g), Cu (7.0 micrograms/g), Fe (73.4 micrograms/g) and Mn (33.6 micrograms/g) were obtained as compared to those of flour, i.e. Ca (0.27 mg/g), P (0.97 mg/g), K (1.64 mg/g), Na (231 micrograms/g), Zn (26 micrograms/g), Cu (4.0 micrograms/g) and Mn (10.5 micrograms/g), respectively. These values were found to be considerably higher than those of wheat. Highly significant positive correlations of ash with sodium and zinc in whole grain were observed. In the case of triticale flour, highly significant positive correlations of ash with manganese, phosphorus and potassium were obtained.