2-methoxy-4a,5,8,8a-tetrahydronaphthalene-1,4-dione

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

Procedure: Little is known, however, concerning the reaction of methoxy and 2,6-dimethoxy-p-benzoquinone. (The latter can be generated from lignin). It has been shown that methoxy-p-benzoquinone will react with 1,3-butadiene to give 2-methoxy-4a,5,8,8a-tetrahydronapthoquinone [G. I. Birnbaum, J. Org. Chem., 25, 1660-1, (1960)]and with 2,3-dimethyl-1,3-butadiene to give 5,8-dihydro-2-methoxy-6,7-dimethyl -1,4-napthoquinone [M. F. Ansell, J. Chem. Soc., 3020, (1963)]. A more recent publication has shown that 2,6-dimethoxy-p-benzoquinone can be combined with isoprene to give a mixture of 2-methoxy-6-methyl-1,4-napthoquinone and 2-methoxy-7-methyl-1,4-napthoquinone [I.-M. TegmoLarsson, Tetra. Letters, 22, 2043-6, (1981)].

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

Procedure: Little is known, however, concerning the reaction of methoxy and 2,6-dimethoxy-p-benzoquinone. (The latter can be generated from lignin). It has been shown that methoxy-p-benzoquinone will react with 1,3-butadiene to give 2-methoxy-4a,5,8,8a -tetrahydronapthoquinone [G. I. Birnbaum, J. Org. Chem., 25, 1660-1, (1960)] and with 2,3-dimethyl-1,3-butadiene to give 5,8-dihydro-2-methoxy-6,7-dimethyl-1,4-napthoquinone [M. F. Ansell, J. Chem. Soc., 3020, (1963)]. A more recent publication has shown that 2,6-dimethoxy-p-benzoquinone can be combined with isoprene to give a mixture of 2-methoxy-6-methyl-1,4-napthoquinone and 2-methoxy-7-methyl-1,4-napthoquinone [I.-M. TegmoLarsson, Tetra. Letters, 22, 2043-6, (1981)].

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

Procedure: A solution of 2-methoxy-4a,5,8,8a-tetrahydronaphthalene-1,4-dione (55, 542 mg, 2.82 mmol) in MeOH (50 mL) was purged with a stream of N2 for 5 min with stirring at rt. With continued N2 purging, solid K2 CO3 (390 mg, 2.82 mmol, Baker) was added to the stirred solution. The solution immediately turned yellow. The reaction was allowed to stir for 15 min at rt under N2, after which it was brown. To this there was added a dilute HCl solution (10% concd HCl, 90% H2O, 50 mL) in one portion. The MeOH was removed in vacuo to give a colorless suspension. The suspended material was collected by filtration, washed with a dilute acid solution (as above, 4×6 mL) and dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC)); mp 142.5°-144° C. (confirmed), lit. (Cavill et al., supra) 123°-124° C. (benzene/petroleum ether); to stir for 15 min at rt under N2 The MeOH was removed in vacuo to give a colorless suspension The suspended material was collected by filtration washed with a dilute acid solution (as above, 4×6 mL) dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC))

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

Procedure: A solution of 2-methoxy-4a,5,8,8a-tetrahydronaphthalene-1,4-dione (55, 542 mg, 2.82 mmol) in MeOH (50 mL) was purged with a stream of N2 for 5 min with stirring at rt. With continued N2 purging, solid K2 CO3 (390 mg, 2.82 mmol, Baker) was added to the stirred solution. The solution immediately turned yellow. The reaction was allowed to stir for 15 min at rt under N2, after which it was brown. To this there was added a dilute HCl solution (10% concd HCl, 90% H2O, 50 mL) in one portion. The MeOH was removed in vacuo to give a colorless suspension. The suspended material was collected by filtration, washed with a dilute acid solution (as above, 4×6 mL) and dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC)); mp 142.5°-144° C. (confirmed), lit. (Cavill et al., supra) 123°-124° C. (benzene/petroleum ether); to stir for 15 min at rt under N2 The MeOH was removed in vacuo to give a colorless suspension The suspended material was collected by filtration washed with a dilute acid solution (as above, 4×6 mL) dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC))

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

Procedure: Little is known, however, concerning the reaction of methoxy and 2,6-dimethoxy-p-benzoquinone. (The latter can be generated from lignin). It has been shown that methoxy-p-benzoquinone will react with 1,3-butadiene to give 2-methoxy-4a,5,8,8a-tetrahydronapthoquinone [G. I. Birnbaum, J. Org. Chem., 25, 1660-1, (1960)]and with 2,3-dimethyl-1,3-butadiene to give 5,8-dihydro-2-methoxy-6,7-dimethyl -1,4-napthoquinone [M. F. Ansell, J. Chem. Soc., 3020, (1963)]. A more recent publication has shown that 2,6-dimethoxy-p-benzoquinone can be combined with isoprene to give a mixture of 2-methoxy-6-methyl-1,4-napthoquinone and 2-methoxy-7-methyl-1,4-napthoquinone [I.-M. TegmoLarsson, Tetra. Letters, 22, 2043-6, (1981)].

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

Procedure: Little is known, however, concerning the reaction of methoxy and 2,6-dimethoxy-p-benzoquinone. (The latter can be generated from lignin). It has been shown that methoxy-p-benzoquinone will react with 1,3-butadiene to give 2-methoxy-4a,5,8,8a-tetrahydronapthoquinone [G. I. Birnbaum, J. Org. Chem., 25, 1660-1, (1960)]and with 2,3-dimethyl-1,3-butadiene to give 5,8-dihydro-2-methoxy-6,7-dimethyl -1,4-napthoquinone [M. F. Ansell, J. Chem. Soc., 3020, (1963)]. A more recent publication has shown that 2,6-dimethoxy-p-benzoquinone can be combined with isoprene to give a mixture of 2-methoxy-6-methyl-1,4-napthoquinone and 2-methoxy-7-methyl-1,4-napthoquinone [I.-M. TegmoLarsson, Tetra. Letters, 22, 2043-6, (1981)].

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

Procedure: A solution of 2-methoxy-4a,5,8,8a-tetrahydronaphthalene-1,4-dione (55, 542 mg, 2.82 mmol) in MeOH (50 mL) was purged with a stream of N2 for 5 min with stirring at rt. With continued N2 purging, solid K2CO3 (390 mg, 2.82 mmol, Baker) was added to the stirred solution. The solution immediately turned yellow. The reaction was allowed to stir for 15 min at rt under N2, after which it was brown. To this there was added a dilute HCl solution (10% concd HCl, 90% H2O, 50 mL) in one portion. The MeOH was removed in vacuo to give a colorless suspension. The suspended material was collected by filtration, washed with a dilute acid solution (as above, 4×6 mL) and dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC)); mp 142.5°-144° C. (confirmed), lit. (Cavill et al., supra) 123°-124° C. (benzene/petroleum ether); 1H NMR (CDCl3) δ2.21 (m, 2H), 3.32 (m, 2H), 3.84 (s, 3H), 4.25 (s, 1H), 5.25 (s, 1H), 5.90 (m, 2H), 6.36 (s, 1H). to stir for 15 min at rt under N2 The MeOH was removed in vacuo to give a colorless suspension The suspended material was collected by filtration washed with a dilute acid solution (as above, 4×6 mL) dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC))

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

Procedure: A solution of 2-methoxy-4a,5,8,8a-tetrahydronaphthalene-1,4-dione (55, 542 mg, 2.82 mmol) in MeOH (50 mL) was purged with a stream of N2 for 5 min with stirring at rt. With continued N2 purging, solid K2CO3 (390 mg, 2.82 mmol, Baker) was added to the stirred solution. The solution immediately turned yellow. The reaction was allowed to stir for 15 min at rt under N2, after which it was brown. To this there was added a dilute HCl solution (10% concd HCl, 90% H2O, 50 mL) in one portion. The MeOH was removed in vacuo to give a colorless suspension. The suspended material was collected by filtration, washed with a dilute acid solution (as above, 4×6 mL) and dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC)); mp 142.5°-144° C. (confirmed), lit. (Cavill et al., supra) 123°-124° C. (benzene/petroleum ether); 1H NMR (CDCl3) δ2.21 (m, 2H), 3.32 (m, 2H), 3.84 (s, 3H), 4.25 (s, 1H), 5.25 (s, 1H), 5.90 (m, 2H), 6.36 (s, 1H). to stir for 15 min at rt under N2 The MeOH was removed in vacuo to give a colorless suspension The suspended material was collected by filtration washed with a dilute acid solution (as above, 4×6 mL) dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC))

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of 2-methoxybenzoquinone (17, 750 mg, 5.43 mmol, TCI, used as received), hydroquinone (38 mg, Matheson, used as received) in toluene (7.5 mL) and butadiene (54, 7.5 mL, Matheson, used as received; Note: condensed butadiene into the toluene with ice bath cooling) contained in a screw top, sealed robe (Ace) was stirred overnight in a 60° C. oil bath. The resulting solution was allowed to cool to rt, then was further cooled in an ice bath. A precipitate formed. The sealed tube was opened. The solid was collected by filtration, washed with hexanes and allowed to air dry (930 mg). The solid was crystallized from hexanes (dissolved in 350 mL, hot filtered, concd to 200 mL, re-filtered, allowed to cool to rt) to yield a yellow powder (703 mg, 68%, >95% pure by 1H NMR analysis); mp 120°-122° C. (hexanes), lit. (Cavill et al., Aust. J. Chem. 26:595-601 (1993)) 126.5°-128° C. (ether); 1H NMR (CDCl3) δ2.21 (m, 2H), 2.51 (m, 2H), 3.16 (m, 1H), 3.26 (m, 1H), 3.79 (s, 3H), 5.69 (m, 2H), 5.90 (s, 1H). cooling) sealed robe (Ace) to cool to rt was further cooled in an ice bath A precipitate formed The solid was collected by filtration washed with hexanes dry (930 mg) The solid was crystallized from hexanes (dissolved in 350 mL, hot filtered, concd to 200 mL, re-filtered, allowed to cool to rt) to yield a yellow powder (703 mg, 68%, >95% pure by 1H NMR analysis)

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A suspension of 2-methoxybenzoquinone (17, 750 mg, 5.43 mmol, TCI, used as received), hydroquinone (38 mg, Matheson, used as received) in toluene (7.5 mL) and butadiene (54, 7.5 mL, Matheson, used as received; Note: condensed butadiene into the toluene with ice bath cooling) contained in a screw top, sealed robe (Ace) was stirred overnight in a 60° C. oil bath. The resulting solution was allowed to cool to rt, then was further cooled in an ice bath. A precipitate formed. The sealed tube was opened. The solid was collected by filtration, washed with hexanes and allowed to air dry (930 mg). The solid was crystallized from hexanes (dissolved in 350 mL, hot filtered, concd to 200 mL, re-filtered, allowed to cool to rt) to yield a yellow powder (703 mg, 68%, >95% pure by 1H NMR analysis); mp 120°-122° C. (hexanes), lit. (Cavill et al., Aust. J. Chem. 26:595-601 (1993)) 126.5°-128° C. (ether); 1H NMR (CDCl3) δ2.21 (m, 2H), 2.51 (m, 2H), 3.16 (m, 1H), 3.26 (m, 1H), 3.79 (s, 3H), 5.69 (m, 2H), 5.90 (s, 1H). cooling) sealed robe (Ace) to cool to rt was further cooled in an ice bath A precipitate formed The solid was collected by filtration washed with hexanes dry (930 mg) The solid was crystallized from hexanes (dissolved in 350 mL, hot filtered, concd to 200 mL, re-filtered, allowed to cool to rt) to yield a yellow powder (703 mg, 68%, >95% pure by 1H NMR analysis)

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

Procedure: Little is known, however, concerning the reaction of methoxy and 2,6-dimethoxy-p-benzoquinone. (The latter can be generated from lignin). It has been shown that methoxy-p-benzoquinone will react with 1,3-butadiene to give 2-methoxy-4a,5,8,8a -tetrahydronapthoquinone [G. I. Birnbaum, J. Org. Chem., 25, 1660-1, (1960)] and with 2,3-dimethyl-1,3-butadiene to give 5,8-dihydro-2-methoxy-6,7-dimethyl-1,4-napthoquinone [M. F. Ansell, J. Chem. Soc., 3020, (1963)]. A more recent publication has shown that 2,6-dimethoxy-p-benzoquinone can be combined with isoprene to give a mixture of 2-methoxy-6-methyl-1,4-napthoquinone and 2-methoxy-7-methyl-1,4-napthoquinone [I.-M. TegmoLarsson, Tetra. Letters, 22, 2043-6, (1981)].

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

Procedure: A solution of 2-methoxy-4a,5,8,8a-tetrahydronaphthalene-1,4-dione (55, 542 mg, 2.82 mmol) in MeOH (50 mL) was purged with a stream of N2 for 5 min with stirring at rt. With continued N2 purging, solid K2 CO3 (390 mg, 2.82 mmol, Baker) was added to the stirred solution. The solution immediately turned yellow. The reaction was allowed to stir for 15 min at rt under N2, after which it was brown. To this there was added a dilute HCl solution (10% concd HCl, 90% H2O, 50 mL) in one portion. The MeOH was removed in vacuo to give a colorless suspension. The suspended material was collected by filtration, washed with a dilute acid solution (as above, 4×6 mL) and dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC)); mp 142.5°-144° C. (confirmed), lit. (Cavill et al., supra) 123°-124° C. (benzene/petroleum ether); to stir for 15 min at rt under N2 The MeOH was removed in vacuo to give a colorless suspension The suspended material was collected by filtration washed with a dilute acid solution (as above, 4×6 mL) dried in vacuo to yield a fluffy colorless solid (444 mg, 82%, pure by 1H NMR analysis (unstable on TLC))