2,4,6-trimethyl-1,3,5-trioxane

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: Paraldehyde One-Step Reaction: To a stirring solution of chromene 4 (350 mg, 1.0 mmol) and PPTS (250 mg, 1.0 mmol) in 1,2-dichloroethane (2 mL) at ambient temperature under N2 was added 3 mL paraldehyde (22.5 mmol). The resulting mixture was refluxed for 7 h. Then, CF3CO2H (1 mL), an additional equivalent of PPTS and 1 mL of paraldehyde were added; the mixture was refluxed overnight. The reaction mixture was neutralized with saturated aqueous NaHCO3 and extracted with ethyl acetate (50 mL×3). The crude product obtained by evaporation under reduced pressure was washed with hexane. The residue was purified by column chromatography eluting with ethyl acetate/hexane (1:2) to afford 100 mg (27% yield) of chromanone 7 and 30 mg (8% yield) of 7a. Chromanone 7 (10,11-trans-dihydro-6,6,10,11-tetramethyl-4-propyl-2H,6H,12H-benzo[1,2-b:3,4-b':5,6-b"]tripyran-2,12-dione) obtained by this method was identical with an authentic sample by comparison of TLC, HPLC and spectroscopic data. The resulting mixture was refluxed for 7 h the mixture was refluxed overnight extracted with ethyl acetate (50 mL×3) The crude product obtained by evaporation under reduced pressure was washed with hexane The residue was purified by column chromatography eluting with ethyl acetate/hexane (1:2)

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 100 g (0.63 mol) of (±)-1-phenyl-1,2-ethanediol (3) (87% pure according to GC) according to Example 1, 200 ml of toluene, 32 g (0.24 mol) of paraldehyde and 1 g of para-toluenesulfonic acid were charged to a 1 l stirrer, heated to boiling (110° C.) and stirred under reflux for a period of 4 h. A total of 10 ml of water were eliminated. After this time, the mixture was cooled to 20° C. and washed until neutral with sodium carbonate solution and water, and the solvent was distilled off under reduced pressure, leaving 103 g of crude product (85.3% pure according to GC). GC conditions see Example 2. were charged to a 1 l stirrer heated (110° C.) under reflux for a period of 4 h washed until neutral with sodium carbonate solution and water the solvent was distilled off under reduced pressure

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

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

Procedure: Tetradecanoyl chloride (40 gms, 0.16 mol), dry paraldehyde (21 gm, 0.16 mol) and anhydrous calcium chloride (2 gms) were refluxed in a 500 ml one-necked flask (protected from atmospheric moisture with a drying guard tube) for 24 hours. The reaction mixture was cooled and chromatographed through a column of Florisil using chloroform as the eluent to give a semisolid product (26 gm, 56%). 1H n.m.r.(CDCl3): δ0.90(3H, t, J=4 Hz, CH3 --), 1.26(22H, s, broad, --[CH2 ]11 --), 1.78(3H, d, J=6 Hz, --CHCH3 --), 2.33(2H, d, J=6 Hz, --COCH2 --), 6.55(1H, q, J=6 Hz, --CHCH3 --). The reaction mixture was cooled chromatographed through a column of Florisil

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

Procedure: A mixture comprising 68 g of paraldehyde, 6 g of caustic potash and 188 g of methanol was added dropwise to a solution comprising 1,000 g of cyclohexanone and 188 g of methanol at 60°-70° C. over a period of 2 hours, and the resulting mixture was stirred for another 3 hours at 60°-70° C. Thereafter, the reaction mixture was decomposed with dilute hydrochloric acid, extracted with ether, washed first with 3% aqueous sodium carbonate, then with saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. After recovering the solvent, the dried product was distilled under vacuum to provide 340 g (yield: 64%) of a fraction boiling at 135°-145° C./3 mm Hg. was added dropwise to a solution at 60°-70° C. of 2 hours extracted with ether washed first with 3% aqueous sodium carbonate with saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate After recovering the solvent the dried product was distilled under vacuum to provide 340 g (yield: 64%) of a fraction boiling at 135°-145° C./3 mm Hg

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

Procedure: A mixture comprising 68 g of paraldehyde, 6 g of caustic potash and 188 g of methanol was added dropwise to a solution comprising 1,000 g of cyclohexanone and 188 g of methanol at 60°-70° C. over a period of 2 hours, and the resulting mixture was stirred for another 3 hours at 60°-70° C. Thereafter, the reaction mixture was decomposed with dilute hydrochloric acid, extracted with ether, washed first with 3% aqueous sodium carbonate, then with saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate. After recovering the solvent, the dried product was distilled under vacuum to provide 340 g (yield: 64%) of a fraction boiling at 135°-145° C./3 mm Hg. was added dropwise to a solution at 60°-70° C. of 2 hours extracted with ether washed first with 3% aqueous sodium carbonate with saturated aqueous sodium chloride, and dried over anhydrous magnesium sulfate After recovering the solvent the dried product was distilled under vacuum to provide 340 g (yield: 64%) of a fraction boiling at 135°-145° C./3 mm Hg

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

Procedure: To a mixture of 2,4,6-trimethyl-1,3,5-trioxane (245 mg, 1.85 mmol) and NaI (0.972 g, 6.48 mmol) in DCM (15 mL) was added a solution of 2-(chlorocarbonyl)phenyl acetate in DCM (5 mL, 0° C.). The resulting mixture was allowed to stir (RT, 16 h). The mixture was filtrated and concentrated under reduced pressure. The crude was purified by silica chromatography (EtOAc—PE, 0-10%) to afford 1-iodoethyl 2-acetoxybenzoate (0.75 g, 40%) as a light yellow oil. The mixture was filtrated concentrated under reduced pressure The crude was purified by silica chromatography (EtOAc—PE, 0-10%)

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

Procedure: To a mixture of 2,4,6-trimethyl-1,3,5-trioxane (245 mg, 1.85 mmol) and NaI (0.972 g, 6.48 mmol) in DCM (15 mL) was added a solution of 2-(chlorocarbonyl)phenyl acetate in DCM (5 mL, 0° C.). The resulting mixture was allowed to stir (RT, 16 h). The mixture was filtrated and concentrated under reduced pressure. The crude was purified by silica chromatography (EtOAc-PE, 0-10%) to afford 1-iodoethyl 2-acetoxybenzoate (0.75 g, 40%) as a light yellow oil: The mixture was filtrated concentrated under reduced pressure The crude was purified by silica chromatography (EtOAc-PE, 0-10%)

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Chlorobutyryl chloride (12.69 g, 90 mmol) was mixed with paraldehyde (3.964 g, 30 mmol) and heated at 85° C. for 90 minutes. Additional paraldehyde (1.35 g) was added and the reaction mixture was stirred at 85° C. for an additional hour. The reaction mixture as cooled to room temperature, diluted with dichloromethane (100 ml) and stirred with saturated aqueous sodium bicarbonate (50 ml) at room temperature for 10 minutes. The dichloromethane layer was separated, dried over sodium sulfate and concentrated in vacuo to yield Cl(CH2)3CO2CHClCH3 which was vacuum distilled (55°-58° C. at 0.1 mm, 9.65 g, 58.6% yield) whose structure was confirmed by NMR. The reaction mixture as cooled to room temperature The dichloromethane layer was separated dried over sodium sulfate concentrated in vacuo

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4-Chlorobutyryl chloride (12.69 g, 90 mmol) was mixed with paraldehyde (3.964 g, 30 mmol) and heated at 85° C. for 90 minutes. Additional paraldehyde (1.35 g) was added and the reaction mixture was stirred at 85° C. for an additional hour. The reaction mixture as cooled to room temperature, diluted with dichloromethane (100 ml) and stirred with saturated aqueous sodium bicarbonate (50 ml) at room temperature for 10 minutes. The dichloromethane layer was separated, dried over sodium sulfate and concentrated in vacuo to yield Cl(CH2)3CO2CHClCH3 which was vacuum distilled (55°-58° C. at 0.1 mm, 9.65 g, 58.6% yield) whose structure was confirmed by NMR. The reaction mixture as cooled to room temperature The dichloromethane layer was separated dried over sodium sulfate concentrated in vacuo