Abstract: A convergent asymmetric synthesis of the antineoplastic macrolide antibiotic cytovaricin has been achieved through the synthesis and coupling of the illustrated spiroketal and polyol glycoside subunits. All absolute stereochemical relationships within the target structure were ultimately controlled by the use of asymmetric aldol, alkylation, or epxidation methodology. Union of the two subunits was accomplished by Julia-Lythgoe ...
![Spiro[21,25-methano-2H,19H,23H-pyrano[2,3-h][1,5]dioxacyclotetracosin-23,2'-[2H]pyran]-19-one,12-[(2,6-dideoxy-3-O-methyl-b-D-ribo-hexopyranosyl)oxy]-3,3',4,4',4a,5',6',7,8,9,10,11,12,13,14,15,16,21,2 Structure](https://image.chemsrc.com/caspic/060/79553-45-0.png)