(4R,5R)-(E)-4,5-dihydroxy-2-hexenoic acid tert-butyl ester

(S)-4-Hydroxymethyl-3-(tetrahydro-pyran-2-yloxy)-dihydro-furan-2-one

(4S,5R,2E)-4,5-epoxyhexenal

(2S,3R)-3-tert-butyldimethylsiloxymethyl-2-tetrahydropyranyloxy-4-butanolide