6-iodo-3,4-dihydro-2H-chromen-4-ol

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

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

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a flame dried round bottom flask containing 6-iodo-chroman-4-ol (3.0 g, 10.8 mmol) and Pd(dppf)Cl2 (0.44 g, 0.54 mmol) was added 6 ml of anhydrous THF and the mixture chilled to 0° C. The mixture was treated with neopentyl zinc chloride (prepared as previously described) (50 ml, 30 mmol, 0.6 M in THF) and stirred under nitrogen at r.t. for 19 h. followed by 5 h at 50° C. (oil bath). The reaction was cooled to r.t. and quenched with NH4Cl and extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated in vacuo to 1.9 g (79%) of a white solid after flash chromatography (10% EtOAc/heptanes, Biotage 40M) Rf=0.11. HRMS (ESI+) calcd for C14H20O2 m/z 220.1463 (M+H)+; found 220.1460. To a flame dried round bottom flask prepared followed by 5 h at 50° C. The reaction was cooled to r.t. quenched with NH4Cl extracted with EtOAc The organic layer was dried over Na2SO4 concentrated in vacuo to 1.9 g (79%) of a white solid after flash chromatography (10% EtOAc/heptanes, Biotage 40M) Rf=0.11

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

Procedure: To a CH2Cl2 (300 ml) suspension of 6-iodo-4-chromanol (15 g, 54.3 mmol) and 30 g of silica gel, at r.t., was added PCC (15.2 g, 70.6 mmol) as a solid. The mixture was stirred at r.t. for 3 h at which time TLC (20% EtOAc/hexanes) indicated complete reaction. The reaction mixture was filtered through a silica gel plug and the filtrate concentrated in vacuo to yield 14.9 g (95%) of 6-iodo-2,3-dihydro-4H-chromen-4-one as a white solid consistent with the literature report (Synthesis 1997, 23-25). HRMS (ESI+) calcd for C9H7IO2 m/z 273.9492; found 273.9500. reaction The reaction mixture was filtered through a silica gel plug the filtrate concentrated in vacuo

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

Procedure: To a solution of 6-iodochroman-4-ol (1.0 g, 3.6 mmol) in 18 ml of THF, at 0° C., was added the Pd(dppf)Cl2.CH2Cl2 (0.15 g, 0.18 mmol), followed by neopentylmagnesium bromide (10.8 ml, 10.8 mmol, 1.0 M in Et2O). The cold bath was maintained for 10 min., then removed and stirring continued overnight. The mixture was quenched with NH4Cl (30 ml) and extracted with EtOAc (3×50 ml). The combined organic layers were dried over MgSO4 and concentrated in vacuo to yield a brown oil. The crude oil was absorbed onto silica gel followed by flash chromatography (biotage 40S) 10% EtOAc/heptanes to yield 0.36 g (46%) of 6-neopentylchroman-4-ol as a white solid. Rf=0.11. HRMS (ESI+) calcd for C14H20O2 m/z 220.1463 (M+H)+; found 220.1460. The cold bath was maintained for 10 min. removed The mixture was quenched with NH4Cl (30 ml) extracted with EtOAc (3×50 ml) The combined organic layers were dried over MgSO4 concentrated in vacuo to yield a brown oil The crude oil was absorbed onto silica gel

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a flame dried round bottom flask containing 6-iodo-chroman-4-ol (3.0 g, 10.8 mmol) and Pd(dppf)Cl2 (0.44 g, 0.54 mmol) was added 6 ml of anhydrous THF and the mixture chilled to 0° C. The mixture was treated with neopentyl zinc chloride (prepared as previously described) (50 ml, 30 mmol, 0.6 M in THF) and stirred under nitrogen at r.t. for 19 h. followed by 5 h at 50° C. (oil bath). The reaction was cooled to r.t. and quenched with NH4Cl and extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated in vacuo to 1.9 g (79%) of a white solid after flash chromatography (10% EtOAc/heptanes, Biotage 40M) Rf=0.11. HRMS (ESI+) calcd for C14H20O2 m/z 220.1463 (M+H)+; found 220.1460. To a flame dried round bottom flask prepared followed by 5 h at 50° C. The reaction was cooled to r.t. quenched with NH4Cl extracted with EtOAc The organic layer was dried over Na2SO4 concentrated in vacuo to 1.9 g (79%) of a white solid after flash chromatography (10% EtOAc/heptanes, Biotage 40M) Rf=0.11

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

Procedure: To a CH2Cl2 (300 ml) suspension of 6-iodo-4-chromanol (15 g, 54.3 mmol) and 30 g of silica gel, at r.t., was added PCC (15.2 g, 70.6 mmol) as a solid. The mixture was stirred at r.t. for 3 h at which time TLC (20% EtOAc/hexanes) indicated complete reaction. The reaction mixture was filtered through a silica gel plug and the filtrate concentrated in vacuo to yield 14.9 g (95%) of 6-iodo-2,3-dihydro-4H-chromen-4-one as a white solid consistent with the literature report (Synthesis 1997, 23-25). HRMS (ESI+) calcd for C9H7IO2 m/z 273.9492; found 273.9500. reaction The reaction mixture was filtered through a silica gel plug the filtrate concentrated in vacuo

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

Procedure: To a solution of 6-iodochroman-4-ol (1.0 g, 3.6 mmol) in 18 ml of THF, at 0° C., was added the Pd(dppf)Cl2.CH2Cl2 (0.15 g, 0.18 mmol), followed by neopentylmagnesium bromide (10.8 ml, 10.8 mmol, 1.0 M in Et2O). The cold bath was maintained for 10 min., then removed and stirring continued overnight. The mixture was quenched with NH4Cl (30 ml) and extracted with EtOAc (3×50 ml). The combined organic layers were dried over MgSO4 and concentrated in vacuo to yield a brown oil. The crude oil was absorbed onto silica gel followed by flash chromatography (biotage 40S) 10% EtOAc/heptanes to yield 0.36 g (46%) of 6-neopentylchroman-4-ol as a white solid. Rf=0.11. HRMS (ESI+) calcd for C14H20O2 m/z 220.1463 (M+H)+; found 220.1460. The cold bath was maintained for 10 min. removed The mixture was quenched with NH4Cl (30 ml) extracted with EtOAc (3×50 ml) The combined organic layers were dried over MgSO4 concentrated in vacuo to yield a brown oil The crude oil was absorbed onto silica gel

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a flame dried round bottom flask containing 6-iodo-chroman-4-ol (3.0 g, 10.8 mmol) and Pd(dppf)Cl2 (0.44 g, 0.54 mmol) was added 6 ml of anhydrous THF and the mixture chilled to 0° C. The mixture was treated with neopentyl zinc chloride (prepared as previously described) (50 ml, 30 mmol, 0.6 M in THF) and stirred under nitrogen at r.t. for 19 h. followed by 5 h at 50° C. (oil bath). The reaction was cooled to r.t. and quenched with NH4Cl and extracted with EtOAc. The organic layer was dried over Na2SO4 and concentrated in vacuo to 1.9 g (79%) of a white solid after flash chromatography (10% EtOAc/heptanes, Biotage 40M) Rf=0.11. HRMS (ESI+) calcd for C14H20O2 m/z 220.1463 (M+H)+; found 220.1460. To a flame dried round bottom flask prepared followed by 5 h at 50° C. The reaction was cooled to r.t. quenched with NH4Cl extracted with EtOAc The organic layer was dried over Na2SO4 concentrated in vacuo to 1.9 g (79%) of a white solid after flash chromatography (10% EtOAc/heptanes, Biotage 40M) Rf=0.11

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

Procedure: To a CH2Cl2 (300 ml) suspension of 6-iodo-4-chromanol (15 g, 54.3 mmol) and 30 g of silica gel, at r.t., was added PCC (15.2 g, 70.6 mmol) as a solid. The mixture was stirred at r.t. for 3 h at which time TLC (20% EtOAc/hexanes) indicated complete reaction. The reaction mixture was filtered through a silica gel plug and the filtrate concentrated in vacuo to yield 14.9 g (95%) of 6-iodo-2,3-dihydro-4H-chromen-4-one as a white solid consistent with the literature report (Synthesis 1997, 23–25). HRMS (ESI+) calcd for C9H7IO2 m/z 273.9492; found 273.9500. reaction The reaction mixture was filtered through a silica gel plug the filtrate concentrated in vacuo

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

Procedure: To a solution of 6-iodochroman-4-ol (1.0 g, 3.6 mmol) in 18 ml of THF, at 0° C., was added the Pd(dppf)Cl2.CH2Cl2 (0.15 g, 0.18 mmol), followed by neopentylmagnesium bromide (10.8 ml, 10.8 mmol, 1.0 M in Et2O). The cold bath was maintained for 10 min., then removed and stirring continued overnight. The mixture was quenched with NH4Cl (30 ml) and extracted with EtOAc (3×50 ml). The combined organic layers were dried over MgSO4 and concentrated in vacuo to yield a brown oil. The crude oil was absorbed onto silica gel followed by flash chromatography (biotage 40S) 10% EtOAc/heptanes to yield 0.36 g (46%) of 6-neopentylchroman-4-ol as a white solid. Rf=0.11. HRMS (ESI+) calcd for C14H20O2 m/z 220.1463 (M+H)+; found 220.1460. The cold bath was maintained for 10 min. removed The mixture was quenched with NH4Cl (30 ml) extracted with EtOAc (3×50 ml) The combined organic layers were dried over MgSO4 concentrated in vacuo to yield a brown oil The crude oil was absorbed onto silica gel

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

Procedure: To a solution of chroman-4-ol (19.6 g, 131 mmol) in CH2Cl2 (500 mL), at rt., was added HgO (29.7 g, 137 mmol) and I2 (34.8 g, 137 mmol) under N2. After stirring for 48 h. the mixture was filtered through a plug of silica gel and the plug washed plug with 30% EtOAc/Hexanes. The filtrate was washed with 15% Na2S2O3 and the organic layer was dried over Na2CO3; filtered and concentrated in vacuo, yielding 6-iodochroman-4-ol as an off-white solid (32.44 g, 90% crude yield). Recrystallization was performed by dissolving product in hot dichloromethane (250 mL) and slowly adding petroleum ether (250 mL). Overall yield 25.9 g, 72% yield. Anal. Calcd for C9H9IO2; C, 39.16, H, 3.29; found C, 39.26, H, 3.27. at rt was filtered through a plug of silica gel the plug washed plug with 30% EtOAc/Hexanes The filtrate was washed with 15% Na2S2O3 the organic layer was dried over Na2CO3 filtered concentrated in vacuo