Preparation and Physical Constants of Acetylenic Compounds

Abstract

We have prepared a series of acetylenic derivatives from sodium acetylides in liquid ammonia by methods which are known.1•2 Modified experimental procedures have supplied in markedly increased yields large quantities of material of good quality, from which samples of high purity

Cobalt(I)‐Mediated Intramolecular [2+2+2] Cocyclizations of (Methylenecyclopropyl)diynes as an Easy Access to Cyclopropanated Oligocycles

“…Solid reagents were dried in vacuo (0.5 to 0.1 Torr). Starting materials: Hepta-1,6-diyne (3), [13] 2-(2-iodoethyl)bicyclopropylidene (5a), [11a] and 1-bromo-4-cyclopropylidenebutane (5c) [11b] were prepared according to previously published procedures. Thin layer chromatography (TLC) was performed on Merck 60 F 254 silica gel or Macherey-Nagel TLC plates Alugram® Sil G/UV254.…”

“…1 H NMR: δ = 0.07 (s, 6 H, 2 CH 3 ), 0.91 (s, 9 H, 3 CH 3 ), 1.72 (quint, J = 7.0 Hz, 2 H, CH 2 ), 1.95 (t, J = 2.6 Hz, 1 H, ϵCH), 2.30 (td, J = 2.6, 7.0 Hz, 2 H, CH 2 ), 2.35 (t, J = 7.0 Hz, 2 H, CH 2 ) ppm. 13 C NMR: δ = -4.5 (2 CH 3 ), 16.5 (C), 17.4 (CH 2 ), 18.9 (CH 2 ), 26.0 (3 CH 3 ), 27.6 (CH 2 ), 68.8 (C), 83.3 (C), 83.5 (C), 106.5 (C) ppm.…”

“…Column chromatography (20 × 6 cm, hexane/benzene, 10:1, R f = 0.38) of the reaction mixture gave enediyne 6a-SitBuMe 2 (9.66 g, 67 %) as a colorless oil. 1 13 C NMR (62.9 MHz, CDCl 3 ): δ = -4.5 (2 CH 3 ), 2.8 (CH 2 ), 2.9 (CH 2 ), 9.7 (CH 2 ), 15.4 (CH), 16.5 (C quat ), 17.9 (CH 2 ), 18.9 (CH 2 ), 19.0 (CH 2 ), 26.0 (3 CH 3 ), 28.2 (CH 2 ), 33.0 (CH 2 ), 79.1 (C quat ), 80.6 (C quat ), 82.9 (C quat ), 107.0 (C quat ), 110.0 (C quat ), 115.3 (C quat ) ppm.…”

“…Different attempts of separation allowed the isolation and the characterization of almost pure major compound 10a: 1 4.49 (s, 5 H), 7.29-7.42 (m, 8 H), 8.20-8.35 (m, 2 H) ppm. 13 C NMR (100 MHz, CDCl 3 ): δ = 8. 2,12.0,16.6,19.4,19.6 (d,J CP = 32 Hz),23.7,24.4,27.4,27.9,29.7,32.6,46.4 (d Butyl(dimethyl)-9-(2Ј-methylenecyclopropyl)nona-1,6-diynylsilane (6b-SitBuMe 2 ): According to GP1, tert-butyl (1,6-heptadiynyl)dimethylsilane (4-SitBuMe 2 , 1.24 g, 6.01 mmol), nBuLi (2.74 mL, 6.30 mmol, 2.3 m in hexanes) and HMPA (1.08 g, 6.03 mmol) were reacted with 1-(2Ј-bromoethyl)-2-methylenecyclopropane (5b, 966 mg, 6.00 mmol) in 15 mL anhydrous THF.…”

“…IR (film): ν = 2985 cm -1 , 2930, 2854, 1688, 1432, 1249, 1223, 1161, 805. 1 (5), 282 (12), 252 (6), 225 (8), 199 (99) [M + -C 5 H 5 -Co -OCH 3 ], 171 (15) [M + -C 5 H 5 -Co -CO 2 CH 3 ], 165 (9), 141 (13), 128 (15), 124 (12), 115 (10), 91 (5), 59 (9) Cyclopentadienyl)(3,4,8,9-η 4 -diphenyl{tetracyclo[7.4.0.0 1,12 .0 4,8 ]trideca-3,8-dien-3-yl}phosphane oxide) -1 , 3053, 2927, 2847, 1435, 1170, 1112, 1099 Butyl(11-cyclopropylideneundeca-1,6-diynyl)dimethylsilane (6c-SitBuMe 2 ): According to GP5, tert-butyl(hepta-1,6-diynyl)dimethylsilane (4-SitBuMe 2 , 894 mg, 4.33 mmol), nBuLi (1.98 mL, 4.55 mmol, 2.3 m in hexanes) and HMPA (774 mg, 4.32 mmol) were reacted with 1-(4Ј-bromobutylidene)cyclopropane (5c, 760 mg, 4.34 mmol) in 10 mL of anhydrous THF. Column chromatography on silica gel (4 × 20 cm, pentane, R f = 0.15) yielded 6c-SitBuMe 2 (883 mg, 68 %) as a colorless oil.…”