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Total syntheses of (–)-7-epi-alexine and (+)-alexine were achieved by using stereoselective allylation via a functionalized pyrrolidine obtained from an extended chiral 1,3-oxazine. The synthetic strategies include pyrrolidine formation via oxazine cleavage and diastereoselective allylations of a pyrrolidine aldehyde. (–)-7-epi-Alexine and (+)-alexine were synthesized from anti,syn,anti-oxazine in 12 steps.

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Concise and stereocontrolled syntheses of (+)-hyacinthacine A2 and sphingofungin B were achieved via a diastereomerically enriched oxazine intermediate. The key strategies include palladium(0)-catalyzed intramolecular oxazine formation and diastereoselective nucleophilic addition to an aldehyde. (+)-Hyacinthacine A2 was synthesized in 13 steps and 10.2% overall yield and the synthesis of sphingofungin B proceeded in a linear sequence over 15 steps and 6.9% overall yield from (R)-methyl 2-benzamido-3-((tert-butyldimethylsilyl)oxy)propanoate.