Synthesis and rearrangement of some 4,5-disubstituted homocubyl derivatives

Synthesis and characterization of some polycyclic cyclobutanones

“…Irradiation of 4 (0.15 M, 254 nm) in cyclohexane or ether produced 4,5-bis(trimethylsiloxy)homocubane (13) in almost quantitative yield. 7 The geometry of the saturated derivative 6 was verified as endo by its NMR spectrum, which again showed the cyclobutene methine a Yields of purified material.…”

“…6% yield. 7 The endo geometry of compound 12 was assumed by analogy, since analysis of the NMR spectrum was inconclusive and 12 failed to undergo photochemical cycloaddition under the conditions described above.…”

“…The ether was washed with saturated NaHC03 solution and dried over Na2S04. After removal of the solvent the residue was vacuum distilled to yield 78.2 g of ester 5 [bp 112-115 °C (2.5 mm), 91%]: mp 52.5-53.5.°C; NMR (CDC13) r 6.33 (s, 6 ), 7.0 (m, 2 H), 7.42 (m, 2 ), 7.91-8.78 (m, 6 H). endo-3,4-Bis(trimethylsiloxy)tricyclo[4.2.1.02'5]non-3-ene (6).…”

“…From 1 mmol of 26 was obtained 152 mg of a 1/2.8 mixture (column 1, 140 °C, 35 ml/ min) of lactones 32 and 31, respectively. Lactone 32: NMR (CC14) 3.83 (m, 2 H), 5.62 (t,J = 9 Hz, 1 H), 6.28 (dd, J = 9, 4 Hz, 1 H), 6.85-7.29 (m, 3 H), 7.62 (m, 1 H), 8.05-8.58 (m, 6 H); ir (CC14) 3040, 2930, 2920, 2860, 1773, 1185, 1170, 1050, 1030, and 710 cm-1; mass spectroscopic molecular weight 178.…”

Strained bridgehead cage alcohols and derivatives

“…The failure of 23b and 23c to undergo efficient cycloaddition in contrast to 23a may result from a combination of the progressively increasing distance between the reactive centers in the higher homologues coupled with the greater reactivity of the more strained norbornene double bond in 23a.26-28 4,5-Dihydroxyhomocubane (25a) was obtained as a white solid in 80% yield by treatment of 24a with dry methanol at room temperature. 26 The diol was readily soluble in polar solvents such as acetone, methanol, pyridine, and DMSO without decomposition. However, in an attempt to record an IR spectrum of 25a in a KBr pellet, a weak carbonyl absorption appeared at 1770 cm-1, implying partial decomposition during pressing.…”