Sodium Carbonate → 3a,6-Epoxy-7-isopropyl-1,4-dimethyl-2,3,3a,4,5,6,7,8-octahydroazulene
Reaction equation
[CH:1]([CH:3]([CH:13]([CH3:15])[CH3:14])[CH2:4][C:5]1[CH:9]([C:10]([CH3:12])=[CH2:11])[CH2:8][CH2:7][CH:6]=1)=[O:2].[Sn](Cl)(Cl)(Cl)Cl.[C:21](=O)([O-])[O-].[Na+].[Na+]>[N+](C)([O-])=O>[O:2]1[CH:1]2[CH2:11][CH:10]([CH3:12])[C:9]31[C:5]([CH2:4][CH:3]2[CH:13]([CH3:15])[CH3:14])=[C:6]([CH3:21])[CH2:7][CH2:8]3Participants
Procedure
To a solution, cooled to -40°, of 3.3 g of 2-(2-formyl-3-methylbutyl)-3-isopropenyl-1-cyclopentene in 225 ml of nitromethane were added 45 ml of a 0.5-M solution of tin tetrachloride in nitromethane. The reaction mixture became intensely yellow in colour and an initially resulting precipitate dissolved again. The mixture was treated immediately with excess 2-N sodium carbonate solution and extracted with ether. After washing, the ethereal phase was dried in a conventional manner and the solvent was removed. Distillation under a high vacuum yielded 2.6 g of crude 3a,6-epoxy-7-isopropyl-1,4-dimethyl-2,3,3a,4,5,6,7,8-octahydroazulene in the form of a colourless oil which could be separated by chromatography on 40 times the amount of Florisil (magnesium silicate gel) with hexane/ether (19:1) into two pairs of epimers (A and B). Epimer A: b.p.0.01 ca 75°; IR(film):νmax = 1465/40, 1380, 1345, 1245, 1162, 1125, 1108, 1080, 1050, 995, 965, 945, 910, 880 cm-1. The odour is camphorous, woody. Epimer B: b.p.0.01 ca 80°IR(film):νmax = 1465/35, 1380, 1340, 1295, 1245, 1200/1195, 1170, 1145, 1110, 1060, 1030, 1000, 990, 950, 925, 910, 878 cm-1. The odour is camphorous, dull.
Workup
- customan initially resulting precipitate
- dissolutiondissolved again
- extractionextracted with ether
- washAfter washing
- customthe ethereal phase was dried in a conventional manner
- customthe solvent was removed
- distillationDistillation under a high vacuum
Sources & evidence
- ORD record
- ord-5aac340fc8444d568e626353a4848354
- Source dataset
- uspto-grants-1976_01
- Patent number
- US03935253
Reaction notes
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