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A common, divergent, and efficient approach to the syntheses of (+)‐steviamine (9), (–)‐1‐deoxy‐8a‐epi‐castanospermine (10), (+)‐trihydroxyindolizidine (11), (+)‐3,7a‐di‐epi‐hyacinthacine A1 (12), and (–)‐2‐epi‐lentiginosine (4) was achieved by starting from D‐ribose‐derived intermediate 13. The key steps involved in these syntheses are a highly diasteroselective Grignard addition to a ribosylimine, a one‐pot stereoselective intramolecular reductive amination, a selectve deprotection of a silyl ether, and a ring‐closing metathesis (RCM) reaction.