Aldehydo-sugars, Aldosuloses, Dialdoses, and Diuloses

The occurrence of 6-deoxy-D-flra6mo-hexofuranos-5-ulose as a component of an antibiotic is noted in Chapter 20. 

Levoglucosenone (l,6-anhydro-3,4-dideoxy- -D- /jc w-hex-3-enopyranosulose) has been identified as a product of the pyrolysis of phenyl j8-D-glucopyrano- 

4sea s Kawakishi, Y. Kito, and M. Namiki, Agric. and Biol. Chem. Japan), 1975, 39, 1897. 

Syntheses of methyl 2,6-dideoxy-4-0-methyl-a-L-er7tAru-hexopyranosid-3-ulose and 3,6-dideoxy-D-ery//fro-hexos-4-ulose are referred to in Chapters 5 and 13, respectively. 

A series of racemic 6-acyl-2-methoxy-5,6-dihydro-(2H)-pyrans (295) has been prepared from the corresponding 6-alkoxycarbonyl derivatives by Claisen condensation with alkyl esters and subsequent decarboxylation of the resulting jS-keto-esters.  

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