Reaction #2320130

Reaction equation

2-methylene-3,4-dihydronaphthalen-1-one

ethyl propenyl ether

→

product

2-ethoxy-3-methyl-3,4,5,6-tetrahydrobenzo[h]chromene

Solvents

dichloroethane

Conditions

Workup

1. 1
   Temperatureat reflux under nitrogen
2. 2
   OtherEvaporation of the solvent
3. 3
   workup.WAITleft 200 g of a brown liquid that
4. 4
   Otherwas purified on a silica gel column with 15/85 ethylacetate/hexane as the eluent

Procedure

A solution of 2-methylene-3,4-dihydronaphthalen-1-one (44.9 g, 282 mmol), tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato)ytterbium [Yb(fod)3, 15.0 g, 14.2 mmo], and ethyl propenyl ether (300 g, 390 mL, 3.5 mol) in 830 mL of dichloroethane was heated at reflux under nitrogen with stirring for 20 hours. Evaporation of the solvent left 200 g of a brown liquid that was purified on a silica gel column with 15/85 ethylacetate/hexane as the eluent, yielding 140 g of product, which was used without further purification.

Source