Benzofuran → 2-Vinyl-7-benzyloxy-6-methoxydihydrobenzofuran

Participants

Role	Name	HCID	Charge
Reactant	Benzofuran	HCID 9223	—
Reactant	trans-2-(4-Hydroxy-3-methoxy-5-nitrophenyl)-4-(3,4,5-trimethoxyphenyl)-1,3-dithiolane	HCID 86749583	—
Reactant	trans-2-(3,4-Dimethoxy-5-nitrophenyl)-4-(3,4,5-trimethoxyphenyl)-1,3-dithiolane	HCID 86750974	—
Reactant	trans-2-(3-(2-Hydroxyethylsufonyl)-5-methoxy-4-propoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-1,3-dithiolane	HCID 86750981	—
Reactant	Butyllithium	HCID 178418339	—
Solvent	Toluene	HCID 1140	—
Solvent	Ethyl Acetate	HCID 8857	—
Product	2-Vinyl-7-benzyloxy-6-methoxydihydrobenzofuran	HCID 19041795	—

Reaction Steps

Using the procedure of Bigi et al, Tetrahedron, 39, 169 (1983), the benzofuran system is constructed. N-butyl lithium (3.95 ml of a 2.2M solution) is added to a solution of 3-benzyloxy-4-methoxyphenol (203, prepared as described in Example 32)(2.0 g, 0.0087 mols) in dry toluene. Upon addition of the n-butyl lithium, a precipitate falls out of solution. After all the n-butyl lithium is added, the reaction is starred for 15-20 minutes at room temperature. Subsequently, the reaction is heated to reflux for twenty one hours. The reaction is then diluted with ethyl acetate and washed with 10% HCl and water. The extract is dried over sodium sulfate. The crude reaction mixture is purified by flash column chromotography using 2:1 hexane-ethyl acetate as eluant to obtain two major products which are (1) unreacted starting material and (2) product (0.979 g, 37.6%)

Provenance & Evidence

DOI	10.6084/m9.figshare.5104873.v1
Patent number	US05639782
Source dataset	uspto-grants-1997_06
ORD ID	ord-3b339500be414512aaae5a6024c2c588
Source note	uspto-grants-1997_06