1-O-Benzyl-β-L-arabinopyranose, 1-O-Benzyl-3,4-O-isopropylidene-β-L-arabinopyranose and 1-O-Benzyl-2-O-benzoyl-3,4-O-isopropylidene-β-L-arabinopyranose

The sugar ring of 1-O-benzyl-β-L-arabinopyranose (C₁₂H₁₆O₅), (I) adopts the ⁴C₁ chair conformation. In 1-O-benzyl-3,4-O-isopropylidene-β-L-arabinopyranose (C₁₅H₂₀O₅), (II) and 1-O-benzyl-2-O-benzoyl-3,4-O-isopropylidene-β-L-arabinopyranose (C₂₂H₂₄O₆), (III), the pyranosyl rings have a slightly distorted chair ⁴C₁ towards ⁰H₁ conformation. The five-membered isopropylidene ring in (II) and (III) adopts a slightly distorted envelope conformation. The methylene carbon atoms of the benzyl group are slightly displaced out of the plane of the phenyl ring in all three crystal structures. All three hydroxy groups in (I) participate in hydrogen bonds each as donor and acceptor simultaneously, forming a two-dimensional hydrogen-bond network. In (II), molecules linked by hydrogen bonds form polymeric chains along the b axis.

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