2-hexylidenecyclopentan-1-one

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 50 ml three-neck flask fitted with a thermometer, a condenser and a stirrer were placed 2-hexylidenecyclopentanone (15 g) synthesized in Reference Example 5 and bromine (0.03 g), followed by 6 hours of the reaction at 100-120° C. The crude product was purified by column chromatography (hexane/ethyl acetate: 95/5) to obtain 12.5 g of 2-hexyl-2-cyclopentenone (GC purity: 98.5%). In a 50 ml three-neck flask fitted with a thermometer, a condenser and a stirrer followed by 6 hours of the reaction at 100-120° C The crude product was purified by column chromatography (hexane/ethyl acetate: 95/5)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In a 300 ml four-neck flask fitted with a thermometer, a reflux condenser and a stirrer were placed 2-(1-hydroxyhexyl)cyclopentanone (85 g) synthesized in Reference Example 2, oxalic acid (1.0 g) and toluene (150 ml), and the whole was refluxed to allow dehydration to proceed. The formed water was removed and the reaction was continued until water was not formed any more (about 3 hours). The reaction mixture was washed with water and the layers were separated from each other. Further, the resulting organic layer was washed with saturated brine and separated. The organic layer was evaporated on a rotary evaporator under reduced pressure to recover toluene and unreacted cyclopentanone, whereby a crude product (78 g) was obtained. The product was distilled using a Claisen distillation apparatus to obtain 67 g of 2-hexylidenecyclopentanone (boiling point: 92° C./533 Pa; GC purity: 98.5%). In a 300 ml four-neck flask fitted with a thermometer, a reflux condenser and a stirrer the whole was refluxed The formed water was removed was not formed any more (about 3 hours) The reaction mixture was washed with water the layers were separated from each other Further, the resulting organic layer was washed with saturated brine separated The organic layer was evaporated on a rotary evaporator under reduced pressure to recover toluene and unreacted cyclopentanone, whereby a crude product (78 g) was obtained The product was distilled a Claisen distillation apparatus

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure of Example 1 is repeated with 98.5 g (0.59 mol) of hexylidene cyclopentanone, 1.61 g (0.072 g-atom) of sodium, 82 g (0.71 mol) of methyl acetoacetate, and 300 ml of methanol. The crude product is fractionated giving 70 g (bp 117°-123° C. at 0.5 mm) of 5-pentylbicyclo [4.3.0] non-1-en-3-one having the structure: ##STR9##

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The procedure of Example 1 is repeated with 98.5 g (0.59 mol) of hexylidene cyclopentanone, 1.61 g (0.072 g-atom) of sodium, 82 g (0.71 mol) of methyl acetoacetate, and 300 ml of methanol. The crude product is fractionated giving 70 g (bp 117°-123° C. at 0.5 mm) of 5-pentylbicyclo [4.3.0] non-1en-3-one having the structure: ##STR9##