Water → HCID 15409727, compound

Participants

Reaction Conditions

Reaction Steps

23 ml (about 1 eq.) of potassium hydride (20% in oil) were placed in a 750 four-necked sulphonation flask provided with a magnetic stirrer, dropping funnel and argon gasification, washed three times with hexane and 120 ml of tetrahydrofuran were added. A solution of 30.4 g (0.11 mol) of 4,6,6-trimethyl-5,6,7,7a-tetrahydro-5-trimethylsilylmethyl-1,3-benzodioxol-5-ol in 200 ml of tetrahydrofuran was added dropwise thereto at 0° C. Subsequently, the suspension was stirred at 20-30° C. for 2 hours. It was again cooled to 0° C. and 200 ml of water were cautiously added dropwise. Subsequent three-fold extraction with 100 ml of hexane each time, washing with saturated sodium chloride solution and drying over anhydrous sodium sulphate gave, after removal of the solvent under reduced pressure, 18.7 g of yellow oil which was subjected to short path distillation under reduced pressure. At 77-85° C./0.75 mbar (7.5 kPa) there were obtained 15.6 g (74% yield) of 4,6,6-trimethyl-5,6,7,7a-tetrahydro-5-methylidene-1,3-benzodioxol as a colorless oil. The content of desired product was 96% according to GC (area %). IR (film, cm−1): 1697, 1600; mass spectrum: 180 (M+, 50), 107 (100); 1H-NMR (C6D6, 400 MHz): inter alia 0.83 and 0.95 (2s, in each case 3H), 1.78 (bs, 3H), 3.9 (m, 1H), 4.59 (s, 1H), 4.70 (s, 1H), 4.75 (s, 1H), 4.91 (s 1H).

Provenance & Evidence