Dichloromethane → HCID 86747606, compound

HRID 1975636Notes

Reaction equation

C(Cl)[Cl:2].C([Li])CCC.[C:9]12([OH:20])[CH2:17][CH:13]([C:14]1([CH3:16])[CH3:15])[CH2:12][CH2:11][C:10]2([OH:19])[CH3:18].[Br:21][CH2:22][CH2:23][CH2:24][CH2:25][CH2:26][B:27]([O-:29])[O-:28]>C1COCC1.[Cl-].[Cl-].[Zn+2]>[C:9]12([OH:20])[CH2:17][CH:13]([C:14]1([CH3:16])[CH3:15])[CH2:12][CH2:11][C:10]2([OH:19])[CH3:18].[Cl:2][C@@H:26]([B:27]([O-:29])[O-:28])[CH2:25][CH2:24][CH2:23][CH2:22][Br:21]

Participants

Conditions

Temperature: -100 °C

Procedure

The desired (+)-pinanediol-(S)-1-chloro-5-bromo-pentane-1-boronate is prepared according to the procedure given in Organometallics 3, 1284 (1984). Therefore methylenechloride (9.8 ml) in THF is cooled to -100° C. and n-butyllithium (71.6 ml 1.6M solution, 114.5 mMol) is added over 20 min. After 15 min at -100° C., a cold (-78° C.) solution of (+)-pinanediol-5-bromo-pentane-1-boronate (32,8 g, 104.1 mMol) in THF is added. After additional 1 hr at -100° C. anhydrous ZnCl2 (7.1 g, 52,0 mMol) in THF is added. After additional 15 min at -100° C. the reaction mixture is warmed to room temperature and stirred for 2 hr at this temperature. The solvent is removed in vacuo, the residue is diluted with hexane/water and is extracted several times with hexane. After drying over Na2SO4 and removal of the solvent in vacuo, (+ )-pinanediol-(S)-1-chloro-5-bromo-pentane-1-boronate is obtained as a yellow oil which is used directly in the next step without further purification.

Workup

customThe desired (+)-pinanediol-(S)-1-chloro-5-bromo-pentane-1-boronate is prepared
customThe solvent is removed in vacuo
additionthe residue is diluted with hexane/water
extractionis extracted several times with hexane
dry with materialAfter drying over Na2SO4 and removal of the solvent in vacuo

Sources & evidence

ORD record: ord-89a98982c6d24e319d3ceb721656a1fa
Source dataset: uspto-grants-1994_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05288707

Reaction notes

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