Ammonia → 1-(2,6,6-Trimethyl-1-cyclohexen-1-yl)-2-buten-1-one

Participants

Reaction Steps

To a mixture of liquid ammonia (250 ml), anhydrous tetrahydrofuran (15 ml), tert-butanol (0.358 g) and 1.002 g (4.84 millimoles) of 2,6,6-trimethyl-1-[3-amino-but-3-enoyl]-cyclohex-1-ene, kept under stirring, there was added sodium metal until the solution acquired a steady blue colour. The reaction mixture was stirred for 15 more minutes and solid ammonium chloride was added thereto until complete discolouration and the ammonia was then evaporated under a stream of argon. After having added to the mixture 25 ml of ether and 75 ml of a concentrated ammonium chloride solution in water, the mixture was extracted with two fractions of 200 ml of ether and 100 ml of chloroform, respectively. The combined organic extracts were dried over anhydrous sodium sulphate, concentrated under reduced pressure and the thus obtained residue (1.038 g) was dissolved in 10 ml of toluene. The said solution was then refluxed overnight, then concentrated under reduced pressure. The thus obtained residue was subjected to a fractional distillation to yield 0.177 g of 2,6,6-trimethyl-1-[but-2-enoyl]-cyclohex-1-ene. The analytical data of the obtained product were identical with those of a pure sample prepared by one of the known methods (cf. Swiss Pat. No. 505,773).

Provenance & Evidence