Bromine → HCID 86753061, compound

Participants

Reaction Conditions

Reaction Steps

2.86 g of (E)-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-but-2-enal were dissolved in 16 ml of CH2Cl2 and cooled to -75° C. 1.1 eq. of Br2 (0.63 ml), dissolved in 3 ml of CH2Cl2, was added drop by drop and the mixture kept for 10 minutes at this temperature. TLC indicated the formation of the dibromide. 4.98 ml of DBU was then added all at once and the temperature raised to 0° C. After 1/2 hour the reaction mixture was poured onto crushed ice/HCl, extracted with EtOEt, washed twice with brine, dried over Na2 SO4 and the solvents removed i.V. Flash chromatography (silica gel, hexane/AcOEt=96:4) yielded 0.95 g of the labile (E)-2-bromo-3-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-naphthalen-2-yl)-but-2-enal as yellow crystals of m.p. 115°-117° C. Double bond geometry was proven by NOE.

Provenance & Evidence