Ein einfacher Weg zu 3′‐Desoxy‐α‐<scp>L</scp>‐ und 3′‐Desoxy‐β‐<scp>D</scp>‐apionucleosiden

A Convenient Route to 3′‐Deoxy‐α‐ L ‐ and 3′‐Deoxy‐β‐ D ‐apionucleosides The cyclic thionocarbonate 3 , easily available in three steps from 3′‐ O ‐benzoyl‐2,3‐ O ‐isopropylidene‐ D ‐apio‐β‐ D ‐furanose ( 1 ), is deoxygenated with n ‐Bu 3 SnH to yield the 3′‐deoxy epimers 4 [methyl 3‐C‐(benzoyloxymethyl)‐3‐deoxy‐α‐ L ‐ threo ‐tetrofuranoside] and 6 [methyl 3‐ C ‐(benzoyloxymethyl)‐3‐deoxy‐β‐ D ‐ erythro ‐tetrofuranoside]. These are separated by chromatography and further converted to the 3′‐deoxy‐α‐ L ‐apionucleosides 11–13 , and the 3′‐deoxy‐β‐ D ‐apionucleosides 17–19 , respectively.