Macrolides, Macrocyclic Lactams and Their Constituent Segments

3 Macrolides, Macrocyclic Lactams and Their Constituent Segments 

Compound 59, the C8-C19 part of the immunosuppressant agent rapamycin, was prepared from diethyl dithioacetal 58.  

The dibranched glycoside 62 from which the C18-C23 subunit of macrolide lasonolide A (63) can be obtained was prepared in several steps from 60 (see Chapter 14 for synthesis) via epoxide 61. Axial epoxide opening with LAH followed by oxidative alkene cleavage and reduction converts 61 to 62.  

Other Oxygen Heterocycles, Indoding Polyether lonophores 

In the area of dioxolanes, enantiomeric chiral equivalents of glycolic acid 67 and 68 were prepared from D-mannitol via tosylates 69 and 70 (bis-acetalization 

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Macrolides, Macrocyclic Lactams, and their Constituent Segments 355... 

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