(−)‐2‐O‐benzyl‐
L
‐Glyceraldehyde and ethyl (R,E)‐4‐O‐benzyl‐4,5‐dihydroxy‐2‐pentenoate
intermediate: diethyl (−)‐2,3‐O‐benzylidene‐L‐tartrate
intermediate: (+)‐2‐O‐benzyl‐L‐threitol
intermediate: (−)‐2‐O‐benzyl‐L‐glyceraldehyde
reactant: Triethyl phosphonoacetate (22.87 g, 102 mmol)
solvent: petroleum ether/ethyl acetate
product: ethyl (−)‐[R‐(E)]‐4‐O‐benzyl‐4,5‐dihydroxy‐2‐pentenoate