Bromoethene → α-Ethenyl-3,4-dihydro-α,4,4-trimethyl-2H-1-benzothiopyran-6-methanol

HRID 1110983Notes

Reaction equation

HRID 1110983 reaction equation
[CH:1]([Mg]Br)=[CH2:2].C(Br)=C.[Mg].[C:9]([C:12]1[CH:13]=[C:14]2[C:19](=[CH:20][CH:21]=1)[S:18][CH2:17][CH2:16][C:15]2([CH3:23])[CH3:22])(=[O:11])[CH3:10].[NH4+].[Cl-]>C1COCC1.CCOCC>[CH3:22][C:15]1([CH3:23])[C:14]2[C:19](=[CH:20][CH:21]=[C:12]([C:9]([OH:11])([CH:1]=[CH2:2])[CH3:10])[CH:13]=2)[S:18][CH2:17][CH2:16]1

Participants

8

Reactant 5

HCID 11641BromoetheneHCID 25517Ammonium ChlorideHCID 5462224MagnesiumHCID 117083551-(4,4-Dimethylthiochroman-6-yl)ethanoneHCID 178418507HCID 178418507, compound

Product 1

HCID 13833716α-Ethenyl-3,4-dihydro-α,4,4-trimethyl-2H-1-benzothiopyran-6-methanol

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To a freshly prepared solution of vinylmagnesium bromide; [7.65 g (0.0715 mol) of vinyl bromide and 1.75 grams (0.0720 g at) of magnesium in 40 mL of dry THF], 10.5 g (0.0477 mol) 6-acetyl-4,4-dimethylthiochroman in 25 mL of THF was added dropwise under N2 in a 200-mL, round-bottom flask equipped with a condenser and nitrogen inlet. The solution was then boiled for 1 hour and allowed to stir for 10 hours at room temperature. Saturated NH4Cl was added in 1-mL portions until the solution was slightly acidic (pH approx. 6.8), and 100 mL of ether was added and the two layers separated. The aqueous layer was extracted with ether (4×100 mL) and the ether extracts were combined with the original organic layer. The combined organics were washed with 50 ml of H2O and 50 mL of brine and was then dried (Na2SO4, 4 h). After evaporation, the resulting oil was used without further purification; IR (neat) 3200-3600 cm-1 (OH); 1H (DCCl3) δ1.32 [s, 6H, (CH3)2C], 1.95 [m, 2H, ArSCH2CH2 ], 2.11 [bs, 1H, OH], 3.00 [m, 2H, ArSCH2CH2 ], 5.14 [dd, 1H, J=2.0 Hz, J=10.5 Hz, CH=CH2 (cis)], 5.30 [dd, 1H, J=2.0 Hz, J=15.0 Hz, CH=CH2 (trans)], 6.16 [dd, 1H, J=10.5 Hz, J=15.0 Hz, CH=CH2 ], 7.05 [d, 1H, J=8 Hz, H(8)], 7.12 [dd, 1H, J=Hz, J=8 Hz, H(7)], 7.52 [d, 1H, J=2 Hz, H(8)]; 13C (DCCl3) ppm 22.9 [ArSCH2CH2 ], 29.1 [CH3COH], 30.2 [(CH3)2C], 33.1 [(CH3)2C], 37.3 [ArSCH2CH2 ], 74.5 [CH3COH], 112.1, 123.2, 126.2, 130.2, 141.6, 142, 144.7. ##STR15##

Workup

  1. customequipped with a condenser and nitrogen inlet
  2. additionwas added
  3. customthe two layers separated
  4. extractionThe aqueous layer was extracted with ether (4×100 mL)
  5. washThe combined organics were washed with 50 ml of H2O and 50 mL of brine
  6. dry with materialwas then dried (Na2SO4, 4 h)
  7. customAfter evaporation
  8. customthe resulting oil was used without further purification

Sources & evidence

ORD record
ord-3e6dbd21e96d4b61b9b4a4aebc523841
Source dataset
uspto-grants-1990_12
Patent number
US04977276

Reaction notes

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