3-propan-2-ylcyclopentan-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: Cyclopentenones designed to test the tolerance of the catalyst to functional groups and steric hindrance were subjected to the reduction conditions. A cyclopentenone that contained an isolated olefin was successfully reduced in high ee (entry 5). Substrates with either a benzyl ether (entry 6) or an ester (entry 7) were also reduced with high enantioselectivity. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times were necessary as the steric bulk of the substituent on the β-carbon increased. For instance, the reduction of 3-isopropylcyclopentenone (entry 8) proceeded to 90% completion after 3 days to afford 3-isopropylcyclopentanone in 88% yield and 94% ee.13,14 To date, attempted reductions of cyclopentenones with vinyl or alkynyl groups conjugated to the enone gave mixtures of products resulting from competing 1,4- and 1,6-reductions. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times increased

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

Procedure: Cyclopentenones designed to test the tolerance of the catalyst to functional groups and steric hindrance were subjected to the reduction conditions. A cyclopentenone that contained an isolated olefin was successfully reduced in high ee (entry 5). Substrates with either a benzyl ether (entry 6) or an ester (entry 7) were also reduced with high enantioselectivity. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times were necessary as the steric bulk of the substituent on the β-carbon increased. For instance, the reduction of 3-isopropylcyclopentenone (entry 8) proceeded to 90% completion after 3 days to afford 3-isopropylcyclopentanone in 88% yield and 94% ee.13,14 To date, attempted reductions of cyclopentenones with vinyl or alkynyl groups conjugated to the enone gave mixtures of products resulting from competing 1,4- and 1,6-reductions. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times increased

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

Procedure: Cyclopentenones designed to test the tolerance of the catalyst to functional groups and steric hindrance were subjected to the reduction conditions. A cyclopentenone that contained an isolated olefin was successfully reduced in high ee (entry 5). Substrates with either a benzyl ether (entry 6) or an ester (entry 7) were also reduced with high enantioselectivity. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times were necessary as the steric bulk of the substituent on the β-carbon increased. For instance, the reduction of 3-isopropylcyclopentenone (entry 8) proceeded to 90% completion after 3 days to afford 3-isopropylcyclopentanone in 88% yield and 94% ee.13,14 To date, attempted reductions of cyclopentenones with vinyl or alkynyl groups conjugated to the enone to gave mixtures of products resulting from competing 1,4- and 1,6-reductions. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times increased

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: A mixture of 3-isopropylcyclopentanone (0.5 g, 3.962 mmol), 1-(5-bromo-2-hydroxyphenyl)ethanone (0.424 g, 1.98 mmol) and pyrrolidine (0.143 g, 1.98 mmol) in MeOH (25 mL) was refluxed overnight. The solvent was removed in vacuo to give crude 6-bromo-3′-isopropylspiro[chroman-2,1′-cyclopentan]-4-one (500 mg, 79%). 1H-NMR (CDCl3): 0.78 (m, 3H), 0.82 (m, 3H), 1.34 (m, 1H), 1.58 (m, 3H), 1.75 (m, 1H), 1.91 (m, 2H), 2.08 (m, 1H0, 2.73 (s, 2H), 6.74 (m, 1H), 7.44 (m, 1H), 7.89 (d, 1H). was refluxed overnight The solvent was removed in vacuo

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of cyclopent-2-enone (1.5 mL, 18.27 mmol), CuBr—SMe2 (188 mg, 0.91 mmol), chlorotrimethylsilane (4.59 mL, 36.54 mmol) amd HMPA (6.55 g, 36.54 mmol) in THF (30 mL) was added isopropylmagnesium bromide (36.54 mL, 1 M in THF) at −70° C. After stirring for 1 h at −70° C., the reaction mixture was quenched with HCl (10%). The mixture was extracted with Et2O. The organic layer was washed with aqueous NaHCO3 and brine. After dried over Na2SO4, the organic layer was concentrated to give 3-isopropylcyclopentanone (4 g, 100%). the reaction mixture was quenched with HCl (10%) The mixture was extracted with Et2O The organic layer was washed with aqueous NaHCO3 and brine After dried over Na2SO4 the organic layer was concentrated

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

Procedure: A mixture of 3-isopropylcyclopentanone (0.5 g, 3.962 mmol), 1-(5-bromo-2-hydroxyphenyl)ethanone (0.424 g, 1.98 mmol) and pyrrolidine (0.143 g, 1.98 mmol) in MeOH (25 mL) was refluxed overnight. The solvent was removed in vacuo to give crude 6-bromo-3′-isopropylspiro[chroman-2,1′-cyclopentan]-4-one (500 mg, 79%). 1H-NMR (CDCl3): 0.78 (m, 3H), 0.82 (m, 3H), 1.34 (m, 1H), 1.58 (m, 3H), 1.75 (m, 1H), 1.91 (m, 2H), 2.08 (m, 1H0, 2.73 (s, 2H), 6.74 (m, 1H), 7.44 (m, 1H), 7.89 (d, 1H). was refluxed overnight The solvent was removed in vacuo

Conditions: temp:-70.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of cyclopent-2-enone (1.5 mL, 18.27 mmol), CuBr—SMe2 (188 mg, 0.91 mmol), chlorotrimethylsilane (4.59 mL, 36.54 mmol) and HMPA (6.55 g, 36.54 mmol) in THF (30 mL) was added isopropylmagnesium bromide (36.54 mL, 1 M in THF) at −70° C. After stirring for 1 h at −70° C., the reaction mixture was quenched with HCl (10%). The mixture was extracted with Et2O. The organic layer was washed with aqueous NaHCO3 and brine. After dried over Na2SO4, the organic layer was concentrated to give 3-isopropylcyclopentanone (4 g, 100%). the reaction mixture was quenched with HCl (10%) The mixture was extracted with Et2O The organic layer was washed with aqueous NaHCO3 and brine After dried over Na2SO4 the organic layer was concentrated

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

Procedure: Cyclopentenones designed to test the tolerance of the catalyst to functional groups and steric hindrance were subjected to the reduction conditions. A cyclopentenone that contained an isolated olefin was successfully reduced in high ee (entry 5). Substrates with either a benzyl ether (entry 6) or an ester (entry 7) were also reduced with high enantioselectivity. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times were necessary as the steric bulk of the substituent on the β-carbon increased. For instance, the reduction of 3-isopropylcyclopentenone (entry 8) proceeded to 90% completion after 3 days to afford 3-isopropylcyclopentanone in 88% yield and 94% ee.13,14 To date, attempted reductions of cyclopentenones with vinyl or alkynyl groups conjugated to the enone gave mixtures of products resulting from competing 1,4- and 1,6-reductions. Examination of the tolerance of the catalyst to steric hindrance on the substrate revealed that longer reaction times increased