1,4-Dioxaspiro[4.5]decan-8-one → 8-(2-Chlorophenylmethylene)-1,4-dioxaspiro[4.5]decane

HRID 727160Notes

Reaction equation

HRID 727160 reaction equation
[Br-].[Cl:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:9][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C([Li])CCC.[CH2:34]1[O:44][C:37]2([CH2:42][CH2:41][C:40](=O)[CH2:39][CH2:38]2)[O:36][CH2:35]1>O1CCCC1>[Cl:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[CH:9]=[C:40]1[CH2:41][CH2:42][C:37]2([O:44][CH2:34][CH2:35][O:36]2)[CH2:38][CH2:39]1

Participants

5

Reactant 3

HCID 5674151,4-Dioxaspiro[4.5]decan-8-oneHCID 167315982-Chlorophenylmethyltriphenylphosphonium bromideHCID 178418339Butyllithium

Product 1

HCID 197052048-(2-Chlorophenylmethylene)-1,4-dioxaspiro[4.5]decaneYield 81.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A stirred solution of 18.0 grams (0.039 mole) of 2-chlorophenylmethyltriphenylphosphonium bromide in about 50 mL of dry tetrahydrofuran was cooled in a dry ice-acetone bath, and 15.4 mL (0.039 mole) of n-butyllithium (2.5M in hexanes) was added dropwise. Upon completion of addition, the reaction mixture was stirred for 1 hour. After this time a solution of 5.0 grams (0.032 mole) of 1,4-cyclohexanedione mono-ethylene ketal in about 5.0 mL of dry tetrahydrofuran was added dropwise. Upon completion of addition, the reaction mixture was allowed to warm to ambient temperature where it was stirred for about 18 hours. After this time the reaction mixture was concentrated under reduced pressure, yielding about 6.9 grams of 8-(2-chlorophenylmethylene)-1,4-dioxaspiro[4.5]-decane. The NMR spectrum was consistent with the proposed structure.

Workup

  1. additionUpon completion of addition
  2. additionUpon completion of addition
  3. stirringwas stirred for about 18 hours
  4. concentrationAfter this time the reaction mixture was concentrated under reduced pressure

Sources & evidence

ORD record
ord-532f7a4bdafe4cc08b5071b1a3b73ac2
Source dataset
uspto-grants-1998_01
Patent number
US05712281

Reaction notes

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