3-methyl-1-((3-methylbut-2-en-1-yl)oxy)but-2-ene

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Methyl 4-hydroxy-3-iodobenzoate (6.0 g, 21.5 mmol) is dissolved in DMF (35 ml) in a dry flask under nitrogen and cooled to 0° C. NaH (60% dispersion in oil, 860 mg, 21.5 mmol) is added portion-wise and the reaction is stirred for 1 h, allowing the ice bath to expire. The mixture is then treated with 1-chloro-3-methyl-2-butene (2.67 ml, 23.7 mmol) and NaI (323 mg, 2.15 mmol), and the reaction is stirred for 18 h at RT. The mixture is diluted with EtOAc (150 ml) and washed with 1:1 saturated NaCl/NaHCO3 (100 ml). The organic layer is dried (MgSO4), concentrated to an oil and chromatographed over 700 g slurry-packed silica gel, eluting with 15% EtOAc/hexane. The appropriate fractions are collected and concentrated to afford 5.13 g of a pale oil. The dimethylallyl ether is dissolved in DMF (40 ml) and treated successively with Pd(OAc)2 (165 mg, 0.74 mmol), Na2CO3 (3.9 g, 36.8 mmol), sodium formate (1.0 g, 14.7 mmol), and n-Bu4NCl.H2O (4.5 g, 16.2 mmol). The mixture is stirred for 2 days at 80° C., then diluted with EtOAc (200 ml) and washed with 50% saturated NaCl (3×75 ml) followed by 5% HCl (75 ml). The organic layer is dried (MgSO4), filtered and concentrated to a brown oil. The crude material is chromatographed over 250 g slurry-packed silica gel, eluting with 10% EtOAc/hexane. The appropriate fractions are collected and concentrated to afford 1.33 g (28% over 2 steps) of methyl 3-isopropyl-1-benzofuran-5-carboxylate as an oil. HRMS (FAB) calcd for C13H14O3+H: 219.1021, found 219.1021 (M+H)+. washed with 50% saturated NaCl (3×75 ml) The organic layer is dried (MgSO4) filtered concentrated to a brown oil The crude material is chromatographed over 250 g slurry-packed silica gel eluting with 10% EtOAc/hexane The appropriate fractions are collected concentrated

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

Procedure: 700 g of a mixture containing 90.2% by weight of 3-methyl-but-3-en-1-al and 5.3% by weight of 3-methyl-but-2-en-1-al, 2,780 g of 3-methyl-but-2-en-1-ol and 6 g of 51% strength aqueous nitric acid are boiled under 100 mm Hg in a 4 liter flask surmounted by a packed column (filled with 5 mm Raschig rings). The bottom temperature assumes a value of from 86 to 93° C. The column has a diameter of 45 mm and has 30 theoretical plates. The water formed in the reaction is taken off at the top of the column and the organic materials which separates from the water is returned continuously into the column. With a reflux of 600 g/hour, quantitative conversion of the aldehyde is achieved in 16 hours. After distilling off the excess alcohol, a mixture consisting of 74.5% by weight of 1,1-bis-(3-methyl-but-2-en-1-yloxy)-3-methyl-but- 3-ene and 10.6% by weight of 1,1-bis-(3-methyl-but-2-en-1-yloxy)-3-methyl-but-2-ene, together with the by-products 3-methyl-butadien-1-yl-3-methyl-but-2-en-1-yl-ether (5.9% by weight) and di-(3-methyl-but-2-en-1-yl)-ether is obtained. The selectivity of the acetals obtained is 86.5% based on the sum of the aldehydes employed and 72.5% based on 3-methyl-but-2-en-1-ol. are boiled under 100 mm Hg in a 4 liter flask surmounted by a packed column (filled with 5 mm Raschig rings) of from 86 to 93° C After distilling off the excess alcohol

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

Procedure: To 30 g of 3-methyl-2-buten-1-ol [prenol] was added 0.74g of p-toluenesulfonic acid, and the mixture was stirred under reflux (at 130°-140° C.) for 3 hours. The reaction solution separated into two layers. The lower layer comprised water and the upper layer was subjected to gas chromatographic analysis revealing that about 4% of the starting prenol remained and that diprenyl ether was formed in a yield of about 50% based on the starting prenol together with unknown products. After distillation under reduced pressure was isolated diprenyl ether having the following properties. under reflux (at 130°-140° C.) for 3 hours The reaction solution separated into two layers

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

Procedure: To 30 g of 3-methyl-2-buten-1-ol [prenol] was added 0.74 g of p-toluenesulfonic acid, and the mixture was stirred under reflux (at 130°-140° C.) for 3 hours. The reaction solution separated into two layers. The lower layer comprised water and the upper layer was subjected to gas chromatographic analysis revealing that about 4% of the starting prenol remained and that diprenyl ether was formed in a yield of about 50% based on the starting prenol together with unknown products. After distillation under reduced pressure was isolated diprenyl ether having the following properties. under reflux (at 130°-140° C.) for 3 hours The reaction solution separated into two layers