An aldopentose is drawn as a Fischer projection with CHO at the top and CH2OH at the bottom. At C2, C3 and C4 the OH groups are all on the left. The sugar is:

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An aldopentose is drawn as a Fischer projection with CHO at the top and $CH X_{2} OH$ at the bottom. At C2, C3 and C4 the OH groups are all on the left. The sugar is:

AL-xylose
BD-lyxose
CD-ribose
DL-ribose

Answer: D

The highest-numbered stereocentre (C4) decides the series: OH on the left means L. D-Ribose has all three OH groups on the right, so the sugar with all three on the left is its mirror image, L-ribose. L-Xylose would have OH on the left at C2 and C4 but on the right at C3.

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An aldopentose is drawn as a Fischer projection with CHO at the top and CHX2​OH at the bottom. At C2, C3 and C4 the OH groups are all on the left. The sugar is:

Answer: D

More questions on Fischer, Newman and sawhorse projections

An aldopentose is drawn as a Fischer projection with CHO at the top and $CH X_{2} OH$ at the bottom. At C2, C3 and C4 the OH groups are all on the left. The sugar is: