1,1,3,3-Tetramethylguanidine → (Z)-3-(1H-indol-5-yl)-2-methoxy-acrylic Acid Benzyl Ester

Participants

Reaction Steps

To a solution of 3.70 g of (1-methoxy-2-benzyloxy-oxoethyl)triphenyl phosphonium chloride in 60 ml of dichloromethane was added at 0° C. 1.07 ml of tetramethyl guanidine and the mixture was warmed to 22° C. The mixture was treated with 2.25 g of 5-formyl-indole and stirring was continued at 40° C. for 16 h. The mixture was treated again with 3.70 g of the Wittig salt and 1.07 ml of tetramethyl guanidine and stirring was continued at 40° for 24 h after which time the conversion was complete. The mixture was evaporated and the residue partitioned between AcOEt and water. The organic layer was dried, evaporated and the residue chromatographed on silica (n-hexane/AcOEt, 4:1) to give 1.67 g of the title compound as a pale yellow oil. MS: (M+H)+ 308.2.

Provenance & Evidence