Picropodophyllin → Podophyllotoxin

HRID 1285478Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:4]=[C:5]([C@H:13]2[C@@H:22]3[C:23]([O:25][CH2:26][C@@H:21]3[C@@H:20]([OH:27])[C:19]3[CH:18]=[C:17]4[O:28][CH2:29][O:30][C:16]4=[CH:15][C:14]2=3)=[O:24])[CH:6]=[C:7]([O:11][CH3:12])[C:8]=1[O:9][CH3:10].[Si](O[Si](C(C)(C)C)(C)C)(C(C)(C)C)(C)C>>[CH3:12][O:11][C:7]1[CH:6]=[C:5]([C@H:13]2[C@H:22]3[C:23]([O:25][CH2:26][C@@H:21]3[C@@H:20]([OH:27])[C:19]3[CH:18]=[C:17]4[O:28][CH2:29][O:30][C:16]4=[CH:15][C:14]2=3)=[O:24])[CH:4]=[C:3]([O:2][CH3:1])[C:8]=1[O:9][CH3:10].[CH3:12][O:11][C:7]1[CH:6]=[C:5]([C@H:13]2[C@@H:22]3[C:23]([O:25][CH2:26][C@@H:21]3[C@@H:20]([OH:27])[C:19]3[CH:18]=[C:17]4[O:28][CH2:29][O:30][C:16]4=[CH:15][C:14]2=3)=[O:24])[CH:4]=[C:3]([O:2][CH3:1])[C:8]=1[O:9][CH3:10]

Participants

Reactant 2

HCID 72435Picropodophyllin

HCID 590018TBDMS ether

Product 2

HCID 10607PodophyllotoxinYield 36%

HCID 72435PicropodophyllinYield 34%

Procedure

In an improvement of the Gensler epimerization, picropodophyllotoxin was converted to the t-butyldimethylsilyl ether. Formation of the enolate with LDA, irreversible quenching with pyridine hydrochloride followed by desilylation afforded 36% podophyllotoxin and 34% picropodophyllotoxin.

Workup

customFormation of the enolate with LDA, irreversible quenching with pyridine hydrochloride

Sources & evidence

ORD record: ord-ba41022d396a43ef99ef243c2185a59a
Source dataset: uspto-grants-1986_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04567253

Reaction notes

Loading…