methyl (3R,5R)-5-(tert-butyldimethylsilyloxy)-3-hydroxy-6-heptenoate

methyl (R)-2-((R)-2-((tert-butyldimethylsilyl)oxy)but-3-en-1-yl)-4-hydroxy-5-oxo-2,5-dihydrofuran-3-carboxylate

(5R,2'R)-3-(benzyloxy)-5-[2'-(tert-butyldimethylsilyloxy)but-3'-enyl]-4-(methoxycarbonyl)furan-2(5H)-one

(R)-4-(benzyloxy)-2-((R)-2-((tert-butyldimethylsilyl)oxy)but-3-en-1-yl)-5-oxo-2,5-dihydrofuran-3-carboxylic acid

(5R,2'R)-3-(benzyloxy)-5-[2'-(tert-butyldimethylsilyloxy)but-3'-enyl]-4-(hydroxymethyl)furan-2(5H)-one