Organic & Biomolecular Chemistry 2015-04-21

Chirality extension of an oxazine building block en route to total syntheses of (+)-hyacinthacine A2 and sphingofungin B.

Seok-Hwi Park, Xiangdan Jin, Jong-Cheol Kang, Changyoung Jung, Seong-Soo Kim, Sung-Soo Kim, Kee-Young Lee, Won-Hun Ham

Index: Org. Biomol. Chem. 13(15) , 4539-50, (2015)

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Abstract

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.