Diethyl Ether → HCID 131714248, compound

HRID 1248619Notes

Reaction equation

HRID 1248619 reaction equation
[CH2:1]([B:8]([OH:10])O)[C:2]1C=CC=CC=1.[C:11]12([OH:22])[CH2:19][CH:15]([C:16]1([CH3:18])[CH3:17])[CH2:14][CH2:13][C:12]2([OH:21])[CH3:20].[Cl:23]C([Li])Cl.O1[CH2:31][CH2:30][CH2:29][CH2:28]1.C(O[CH2:35][CH3:36])C>[Cl-].[Zn+2].[Cl-]>[Cl:23][C@@H:1]([B:8]([O:22][C:11]12[CH2:19][CH:15]([C:16]1([CH3:18])[CH3:17])[CH2:14][CH2:13][C:12]2([OH:21])[CH3:20])[OH:10])[CH2:2][C:36]1[CH:35]=[CH:31][CH:30]=[CH:29][CH:28]=1

Participants

6

Reactant 4

HCID 3283Diethyl EtherHCID 8028TetrahydrofuranHCID 86740164HCID 86740164, compoundHCID 178506907HCID 178506907, compound

Product 1

HCID 131714248HCID 131714248, compound

Reagents, catalysts & solvents 1

HCID 3007855ZincchlorideCatalyst

Procedure

##STR20## The procedure of Example 1 was followed, with 6.75 g (25 mmol) of (+)-pinanediol benzylboronate, 27 mmol of dichloromethyllithium, 30 mL of tetrahydrofuran, 20 mL of diethyl ether, and 1.75 g (12.8 mmol) of anhydrous zinc chloride. NMR analysis indicated that the reaction was complete after 3.5 hr at 20°-25° C. When the petroleum ether extracts were concentrated, the residue crystallized and 7.9 g. (99%) was recovered. The recovered product was shown to be pure (+)-pinanediol (1S)-1-chloro-2-phenylethane-1-boronate by 200 MHz proton NMR analysis, with less than 0.5% of the (1R) isomer present. This was confirmed by comparison with an epimerized sample consisting of approximately equal amounts of the (1S) and (1R) isomers, which show distinctive peaks in the multiplet near δ 3.65 (especially the (1R) peaks at 718.6 Hz and 735.2 Hz and the (1S) peaks at 722.4 and 738.6 Hz downfield from tetramethylsilane). (For the preparation of this compound without the aid of zinc chloride catalysis, see Matteson et al., J. Am. Chem. Soc., Vol. 103, pp 52-5242 (1981).

Workup

  1. concentrationWhen the petroleum ether extracts were concentrated
  2. customthe residue crystallized
  3. custom(99%) was recovered
  4. custom(For the preparation of this compound without the aid of zinc chloride catalysis

Sources & evidence

ORD record
ord-c1160aeac91649169dbdf194fb1ab6b2
Source dataset
uspto-grants-1985_06
Patent number
US04525309

Reaction notes

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