Sodium Carbonate → 3-Methyl-8-methylidene-1,2,4,5,6,7,8,8a-octahydroazulen-6-ol

Participants

Reaction Steps

To a solution, cooled to 0°, of 57 g of 3-isopropenyl-1-methyl-2-(3-oxopropyl)-1-cyclopentene in 3 l of absolute benzene and 800 ml of absolute ether were added dropwise under a nitrogen atmosphere within 30 minutes 900 ml of a 0.5 M solution of tin tetrachloride in benzene. The mixture was stirred for a further 30 minutes at 5°, whereby it became red coloured, then treated at 0° with saturated sodium carbonate solution up to an alkaline reaction and suction filtered. The benzene solution was washed with saturated sodium carbonate solution and water, dried with anhydrous sodium sulphate and evaporated under reduced pressure. The crude product obtained was fractionated on a short column with the addition of 2 g of anhydrous potash. There were obtained 41 g (yield 72%) of 6-hydroxy-1-methyl-4-methylen-2,3,3a,4,5,6,7,8-octahydroazulene b.p.0.5 90°-92°; nD20 = 1.5233; IR(film):νmax = 3450, 3090, 1640, 1450, 1440, 1380, 1200, 1155, 1098, 1080, 1060, 1030, 942, 890, 775 cm-1. The compound has a flowery, camphorous, woody odour.

Provenance & Evidence