Linalyl acetoacetate → (+/-)-Linalyl (2-naphthoyl)acetate

HRID 634590Notes

Reaction equation

[C:1]([O:7][C:8]([CH2:12][CH2:13][CH:14]=[C:15]([CH3:17])[CH3:16])([CH:10]=[CH2:11])[CH3:9])(=[O:6])[CH2:2][C:3]([CH3:5])=[O:4].[CH:18]1[C:27]2[C:22](=[CH:23][CH:24]=C[CH:26]=2)[CH:21]=[CH:20][C:19]=1C(CC([O-])=O)=O>>[CH:26]1[C:27]2[C:22](=[CH:21][CH:20]=[CH:19][CH:18]=2)[CH:23]=[CH:24][C:5]=1[C:3](=[O:4])[CH2:2][C:1]([O:7][C:8]([CH3:9])([CH2:12][CH2:13][CH:14]=[C:15]([CH3:17])[CH3:16])[CH:10]=[CH2:11])=[O:6]

Participants

Reactant 2

HCID 11791251Linalyl acetoacetate

HCID 212602322-Naphthoylacetate

Product 1

HCID 10991722(+/-)-Linalyl (2-naphthoyl)acetate

Procedure

Crude 3,7-dimethyl-1,6-octadien-3-yl 3-oxo-butyrate (154.51, 0.648 mol) from above is placed in a 3000 mL three-necked round-bottomed flask fitted with a condenser, argon inlet, addition funnel, magnetic stirrer and internal thermometer. The contents are dissolved in 350 mL of dichloromethane and treated with powdered calcium hydroxide (50.44 g, 0.681 mol). The mixture is stirred at 30° C. for 30 min and then heated to 40° C. 2-Naphthoyl chloride (142.12 g, 0.746 mol) dissolved in 20 mL of dichloromethane is added dropwise over 15 min. The mixture continues to be heated at this temperature for 1 h. Ammonium chloride (36.41 g, 0.681 mol) dissolved in 250 mL of water is added to the reaction mixture and the pH adjusted to ˜9 with 28% ammonium hydroxide. After stirring 30 min at 35° C. the pH is adjusted to ˜1 with 20% HCl. The mixture is transferred to a separatory fumnel containing diethyl ether (500 mL) and water (500 mL). The layers are separated and the organic phase is washed with saturated NaHCO3 solution (2×500 mL), dried over MgSO4, filtered and concentrated by rotary evaporation to give a yellow red oil. At this point a light yellow solid precipitates from the mixture. An equal volume of hexane is added and the solids is collected by filtration and dried. NMR analysis indicates the solid is 2-naphthoic acid. The eluent is concentrated again by rotary evaporation to give a red oil. The oil is taken up in an equal volume of dichloromethane, passed through a plug of silica gel (400 g) and eluted with dichloromethane. The mixture is concentrated by rotary evaporation and stripped by Kugelrohr distillation (40° C., 0.10 mm Hg, 30 min) to yield 173.26 g (76.3%) of the product as a red oil; this product is a mixture of a 1:10 molar ratio of linalyl acetoacetate to linalyl (2-naphthoylacetate. A portion of this material is purified by column chromatography (elution with 2.5% ethyl acetate in hexanes) to give the desired product as a light yellow oil.

Workup

additiona mixture of a 1
customA portion of this material is purified by column chromatography (elution with 2.5% ethyl acetate in hexanes)

Sources & evidence

ORD record: ord-4ab60493015a4311ba363cd8dc95f7f0
Source dataset: uspto-grants-2001_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06184188B2

Reaction notes

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