(E)-(4R,5R)-4-[(2R,3R,4S,5R,6R)-5-(tert-Butyl-dimethyl-silanyloxy)-3,4-dimethoxy-6-methyl-tetrahydro-pyran-2-yloxymethyl]-5-hydroxy-2-methyl-hept-2-enal

O-mycinosyltylonolide

(E)-(4R,5R)-5-Acetoxy-4-hydroxymethyl-2-methyl-hept-2-enoic acid ethyl ester