Lichen macrolactone

Using FmA catalysis and protected 4-hydroxybutanal, compound (97) has been stereoselectively prepared as a synthetic equivalent to the C-3-C-9 fragment of (-F)-aspicillin, a lichen macrolactone (Figure 10.35) [160]. Similarly, FruA mediated stereoselective addition of (25) to a suitably crafted aldehyde precursor (98) served as the key step in the synthesis of the noncarbohydrate , skipped polyol C-9-C-16 chain fragment (99) of the macrolide antibiotic pentamycin [161,162]. 

Figure 10.35 Stereoselective generation of chiral precursors for the synthesis of the lichen macrolactone (+)-aspicillin and the macrolide antibiotic pentamycin using FruA catalysis.

Suwarso, W., Priyono, Gani, R. L., Krohn, K., and John, M. (1999). Dasypogalactone, a new C3-symmetric macrolactone from the Indonesian lichen Usnea dasypoga. Eur. J. Org. Chem. 1719-1721. 

Unusual macrolactone glycosides (52-53) and acetylinic lipids (19-28), obtained from Cetraria islandica (L.) Ach., are suspected to maintain the membrane integrity and liquid water balance in lichens occurring in regions with low temperatures [3,48,49]. Polysaccharides and polyols account for up... 

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