Synthesis of Asperuloside Aglucon Silyl Ether and Garjasmine from (+)-Genipin via Gardenoside Aglucon Bis(silyl ether) as a Common Intermediate

Nakatani, Kazuhiko; Shimano, K.; Hiraishi, Atsushi; Han, Qingjun; Isoe, Sachihiko

doi:10.1246/bcsj.66.2646

Cited by 6 publications

(1 citation statement)

References 10 publications

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“…Subsequently, we prepared asperuloside tetraacetate (34) as the dienophile (Scheme 3). Known compound 27 35 arising from (+)-genipin (12) was subjected to a sequence of acetylation, silylation, and selective deprotection of the less hindered silyl ether, to give lactol 36 as a mixture of two anomers in a ca. 1:1 ratio.…”

Section: Exposure Of This Compound To Lawesson Reagent Furnished 21mentioning

confidence: 99%

Total Synthesis of Hybridaphniphylline B

et al. 2018

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Hybridaphniphylline B (1) is a Daphniphyllum alkaloid possessing 11 rings and 19 stereocenters. Here we report the first total synthesis of 1 featuring a late-stage intermolecular Diels-Alder reaction of a fully elaborated cyclopentadiene and asperuloside tetraacetate. The diene was prepared on the basis of a scalable route to daphnilongeranin B (4). Claisen rearrangement of an allyl dienol ether was exploited as a key step; the subtle variation of the substrate and use of protic solvents suppressed the undesired Cope rearrangement. Daphniyunnine E (6) and dehydrodaphnilongeranin B (7), two congeners of 4, were also synthesized. The dienophile arose from (+)-genipin through glycosylation and lactonization. A one-pot protocol was developed for the diene formation and Diels-Alder reaction; one of the cycloadducts was converted into 1 through reductive desulfurization and global deacetylation.

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Section: Exposure Of This Compound To Lawesson Reagent Furnished 21mentioning

confidence: 99%