Monosaccharides having a carbon-carbon double
bond anywhere in the backbone chain.
Glycals (term not recommended) designates the enoses that are generated by formal
elimination of the hemiacetal hydroxy
group and an adjacent hydrogen
atom. Thus
glycals are cyclic enol
ethers. 2-Carb-17. Unsaturated hexoses, for example, are called hexenoses. E.g.

(the hex-1-enopyranose derived from D-glucopyran
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