1,1,2,3,3-pentamethyl-2,3a,5,6,7,7a-hexahydroinden-4-one

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,2,3,3-Pentamethyl-octahydro-inden-4-one is first prepared by the hydrogenation of 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF). 1,1,2,3,3-Pentamethyl-hexahydro-indene-4,5-dione is subsequently prepared with 1,1,2,3,3-pentamethyl-octahydro-inden-4-one (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-hexahydro-indene-4,5-dione (10 g, 0.04 mol), ethylene diamine (NH2CH2CH2NH2) (2.5 g, 0.04 mol), and diglyme (50 mL). The reaction mixture is heated to 130° C. and stirred for 24 hours. The reaction mixture is then cooled to 25° C. and further oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (10 g, 0.045 mol) for another 8 hours. The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Diglyme is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product 7,7,8,9,9-pentamethyl-5,6a,7,8,9,9a-hexahydro-6H-cyclopenta[f]quinoxaline (˜10 g) is obtained. A 100 mL reaction flask The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) Diglyme is recovered by roto-evaporation The crude product is further purified with liquid chromatography (Biotage® system) crystallized

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,2,3,3-Pentamethyl-octahydro-inden-4-one is first prepared by the hydrogenation of 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF). 1,1,2,3,3-Pentamethyl-hexahydro-indene-4,5-dione is subsequently prepared with 1,1,2,3,3-pentamethyl-octahydro-inden-4-one (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-hexahydro-indene-4,5-dione (10 g, 0.04 mol), thioacetamide (3.5 g, 0.04 mol), and diglyme (50 mL). The reaction mixture is heated to 130° C. and stirred for 24 hours. The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Diglyme is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product 2,6,6,7,8,8-hexamethyl-5,5a,6,7,8,8a-hexahydro-4H-3-thia-1-aza-as-indacene (˜10 g) is obtained. A 100 mL reaction flask The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) Diglyme is recovered by roto-evaporation The crude product is further purified with liquid chromatography (Biotage® system) crystallized

Conditions: temp:200.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,2,3,3-Pentamethyl-octahydro-inden-4-one is first prepared by the hydrogenation of 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF). 1,1,2,3,3-Pentamethyl-hexahydro-indene-4,5-dione is subsequently prepared with 1,1,2,3,3-pentamethyl-octahydro-inden-4-one (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-hexahydro-indene-4,5-dione (10 g, 0.04 mol) and formamide (50 mL). The reaction mixture is heated to 200° C. and stirred for 24 hours. The crude mass is diluted with toluene (50 mL) and then washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Toluene is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product of a mixture of 6,6,7,8,8-pentamethyl-5,5a,6,7,8,8a-hexahydro-4H-1-oxa-3-aza-as-indacene and 6,6,7,8,8-pentamethyl-5,5a,6,7,8,8a-hexahydro-4H-indeno[4,5-d]oxazole (˜10 g) is obtained. A 100 mL reaction flask washed once with aqueous sodium carbonate (10%, 100 mL) Toluene is recovered by roto-evaporation The crude product is further purified with liquid chromatography (Biotage® system) crystallized Product of a mixture of 6,6,7,8,8-pentamethyl-5,5a,6,7,8,8a-hexahydro-4H-1-oxa-3-aza-as-indacene

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,2,3,3-Pentamethyl-octahydro-inden-4-one is first prepared by the hydrogenation of 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF). 1,1,2,3,3-Pentamethyl-hexahydro-indene-4,5-dione is subsequently prepared with 1,1,2,3,3-pentamethyl-octahydro-inden-4-one (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-hexahydro-indene-4,5-dione (10 g, 0.04 mol), ethylene diamine (NH2CH2CH2NH2) (2.5 g, 0.04 mol), and diglyme (50 mL). The reaction mixture is heated to 130° C. and stirred for 24 hours. The reaction mixture is then cooled to 25° C. and further oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (10 g, 0.045 mol) for another 8 hours. The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Diglyme is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product 7,7,8,9,9-pentamethyl-5,6a,7,8,9,9a-hexahydro-6H-cyclopenta[f]quinoxaline (˜10 g) is obtained. A 100 mL reaction flask The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) Diglyme is recovered by roto-evaporation The crude product is further purified with liquid chromatography (Biotage® system) crystallized

Conditions: temp:130.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,2,3,3-Pentamethyl-octahydro-inden-4-one is first prepared by the hydrogenation of 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF). 1,1,2,3,3-Pentamethyl-hexahydro-indene-4,5-dione is subsequently prepared with 1,1,2,3,3-pentamethyl-octahydro-inden-4-one (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-hexahydro-indene-4,5-dione (10 g, 0.04 mol), thioacetamide (3.5 g, 0.04 mol), and diglyme (50 mL). The reaction mixture is heated to 130° C. and stirred for 24 hours. The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Diglyme is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product 2,6,6,7,8,8-hexamethyl-5,5a,6,7,8,8a-hexahydro-4H-3-thia-1-aza-as-indacene (˜10 g) is obtained. A 100 mL reaction flask The crude mass is washed once with aqueous sodium carbonate (10%, 100 mL) Diglyme is recovered by roto-evaporation The crude product is further purified with liquid chromatography (Biotage® system) crystallized

Conditions: temp:200.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 1,1,2,3,3-Pentamethyl-octahydro-inden-4-one is first prepared by the hydrogenation of 1,1,2,3,3-pentamethyl-1,2,3,5,6,7-hexahydro-inden-4-one (Cashmeran®) (commercially available at IFF). 1,1,2,3,3-Pentamethyl-hexahydro-indene-4,5-dione is subsequently prepared with 1,1,2,3,3-pentamethyl-octahydro-inden-4-one (prepared as described by Barton in Tetrahedron Letters, 1984, 25(6), pages: 603-606). A 100 mL reaction flask is charged with 1,1,2,3,3-pentamethyl-hexahydro-indene-4,5-dione (10 g, 0.04 mol) and formamide (50 mL). The reaction mixture is heated to 200° C. and stirred for 24 hours. The crude mass is diluted with toluene (50 mL) and then washed once with aqueous sodium carbonate (10%, 100 mL) followed by twice with brine (30 mL). Toluene is recovered by roto-evaporation. The crude product is further purified with liquid chromatography (Biotage® system) and then crystallized. Product of a mixture of 6,6,7,8,8-pentamethyl-5,5a,6,7,8,8a-hexahydro-4H-1-oxa-3-aza-as-indacene and 6,6,7,8,8-pentamethyl-5,5a,6,7,8,8a-hexahydro-4H-indeno[4,5-d]oxazole (˜10 g) is obtained. A 100 mL reaction flask washed once with aqueous sodium carbonate (10%, 100 mL) Toluene is recovered by roto-evaporation The crude product is further purified with liquid chromatography (Biotage® system) crystallized Product of a mixture of 6,6,7,8,8-pentamethyl-5,5a,6,7,8,8a-hexahydro-4H-1-oxa-3-aza-as-indacene