(3R,4S,5R)-5-Ethyl-3-hydroxy-4-trityloxymethyl-dihydro-furan-2-one

(E)-(4R,5R)-5-Hydroxy-2-methyl-4-trityloxymethyl-hept-2-enal

(E)-(4R,5R,6R)-4,6-Dihydroxy-3-methyl-5-trityloxymethyl-oct-2-enoic acid methyl ester