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Chemistry of odorants: stereoselective synthesis of octahydronaphthalene-based perfumery Georgywood, (+,−)-1-[(1R∗,2S∗)-1,2,3,4,5,6,7,8-octahydro-1,2,8,8-tetramethylnaphthalen-2-yl]ethan-1-one

“…1-(2- 2,3,4,5,6,7,ethan-1-one, 6. 3-Bromo-but-3-en-2-one 5 28 (2.1 g, 14 mmol) in dry CH 2 Cl 2 (40 mL) was stirred with SnCl 4 (1.08 g, 0.41 mmol), at 278 8C under argon for 30 min, then myrcene (1.9 g, 14 mmol) was added dropwise and the reaction mixture was stirred for 4 h and then was allowed to warm up to room temperature.…”

“…After 2 h, the organic layer was washed with water (2£10 mL), saturated bicarbonate solution (3£10 mL), brine (2£5 mL), dried over Na 2 SO 4 and concentrated in vacuo to give a crude product that was purified by flash chromatography (hexane/ethyl acetate 9/1) to provide 6 (140 mg, yield 70%). 4,5,6,7,ethan-1-one, 10. To a stirred solution of 6 (1.0 g, 3.5 mmol) in dry CH 2 Cl 2 (5 mL), DBU (1.06 g, 7.0 mmol) was added dropwise at 0 8C under argon.…”

“…Compound 7 (1.0 g, 3.5 mmol) and DBU (1.06 g, 7.0 mmol), under the same reaction conditions and purification to prepare 10, gave 11 as viscous oil (651 mg, yield 91%). IR n max (CHCl 3 )/cm 21 : 1680, 1640, 1369, 1217, 1110 135.3; 134.0; 132.2; 123.5; 118.9; 37.6; 27.5; 26.0; 25.7; 25.0; 20.4; 17.7 2,3,4,5,6,7,8,ethan-1-one, 13 (as inseparable trans/ cis diastereoisomeric mixture). Method a.…”

“…IR n max (CHCl 3 )/cm 21 : 3370, 1660, 1358, 1110 (1,2)-1-[(1R p ,2S p )-1,2,3, 4,5,6,7,2,8,ethan-1-one, Georgywood, 3. A trans/cis mixture of 13 (160 mg, 0.72 mmol) was dissolved in dry THF (10 mL) under argon at 0 8C, then NaH (70 mg, 2.9 mmol) and CH 3 I (750 mg, 5.28 mmol) were added.…”

“…As a consequence, numerous structural analogues of 2 were synthesized, of which Georgywood 3 was found to be one of best, showing the same odor threshold and possessing a very attractive warmwoody, sweet-powdery smell. 4 The strategy for the synthesis of Georgywood 3 includes the well-known and previously described two step sequence: first, the Lewis acid-activated Diels -Alder reaction of homomyrcene 5 with methyl isopropenyl ketone, then the subsequent acid-catalyzed cyclization of the cyclohexene intermediate to 3. 5 In this publication, we report a new synthesis of octahydronaphthalene-type odorants, such as 3, by a general strategy which should make the bicyclic intermediates synthetically more accessible.…”