2-Hydroxyisobutyric acid → 2-hydroxy-2-methyl-propionic acid(S)-2-[(1R,3aR,4S,7aR)-4-(tert-butyl-dimethyl-silanyloxy)-7a-methyl-octahydro-inden-1-yl]-propyl ester

HRID 400224

Reaction equation

[C:1]([Si:5]([CH3:22])([CH3:21])[O:6][C@H:7]1[CH2:15][CH2:14][CH2:13][C@@:12]2([CH3:16])[C@H:8]1[CH2:9][CH2:10][C@@H:11]2[C@H:17]([CH3:20])[CH2:18][OH:19])([CH3:4])([CH3:3])[CH3:2].C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.CCOC(/N=N/C(OCC)=O)=O.[OH:54][C:55]([CH3:60])([CH3:59])[C:56](O)=[O:57]>C1COCC1.O>[C:1]([Si:5]([CH3:22])([CH3:21])[O:6][C@H:7]1[CH2:15][CH2:14][CH2:13][C@@:12]2([CH3:16])[C@H:8]1[CH2:9][CH2:10][C@@H:11]2[C@H:17]([CH3:20])[CH2:18][O:19][C:56](=[O:57])[C:55]([OH:54])([CH3:60])[CH3:59])([CH3:3])([CH3:4])[CH3:2]

Participants

Conditions

Temperature: 0 °C

Procedure

200 mg (0,612 mmol) of (S)-2-[(1R,3aR,4S,7aR)-4-(tert-butyl-dimethyl-silanyloxy)-7a-methyl-octahydro-inden-1-yl]-propan-1-ol was dissolved in THF (2 ml). PPh3 (169 mg; 0,643 mmol) was added and the mixture cooled to 0° C. To this, a solution of DEAD (95 mg; 0,612 mmol) and 2-hydroxy-isobutyric acid (64 mg; 0,612 mmol) in THF (2 ml) was added dropwise via cannula. After four hours the reaction mixture was poured in cold water, extracted with ether and dried over Na2SO4. Removal of the solvent and silica gel column chromatography (eluent hexane/ethyl-acetate 85/15) of the residue afforded 232 mg (91%) of 2-hydroxy-2-methyl-propionic acid(S)-2-[(1R,3aR,4S,7aR)-4-(tert-butyl-dimethyl-silanyloxy)-7a-methyl-octahydro-inden-1-yl]-propyl ester (K1) as a yellow oil.

Workup

extractionextracted with ether
dry with materialdried over Na2SO4
customRemoval of the solvent and silica gel column chromatography (eluent hexane/ethyl-acetate 85/15) of the residue

Sources & evidence

ORD record: ord-7c1d61e2cebd4a67bc256db3185810d7
Source dataset: uspto-grants-1998_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05827883

Linked notes

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