Molecular and crystal structure of 23,24,25,26,27,29,30-heptamethyl-19,28-oxahexacyclo[15.13.18.017,18.013,14.08,9.05,10]tetracos-3-yl acetate

The molecular structure of 23,24,25,26,27,29,30-heptamethyl-19,28-oxahexacyclo[15.13.18.0^17,18.0^13,14.0^8,9.0^5,10]tetracos-3-yl acetate III. Compound III C₃₂H₅₂O₃ crystallizes in the monoclinic crystal system with the unit cell parameters a = 13.265(15) ?, b = 6.481(7) ?, c = 32.274(4) ?, β = 99.333(2)°, space group C2, Z = 4, d = 1.176 g/cm³. Original Russian Text Copyright ? 2009 by N. I. Medvedeva, O. B. Flechter, and A. A. Korlyukov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 399–401, March–April, 2009.     

Molecular structure of methyl-10,14,19,19-tetramethyl-4-oxo-20-oxahexacyclo [15.3.1.16.18.06.15.09.14017.21]docosane-10-carboxylate

The synthesis of methyl-10,14,19,19-tetramethyl-4-oxo-20-oxahexacyclo[15.3.1.1^6.18.0^6.15.0^9.140^17.21] docosane-10-carboxylate III is performed and its molecular structure is determined. Compound III C₂₇H₄₀O₄ crystallizes in the monoclinic system with the cell parameters as follows: a = 12.8081(11) ?, b = 7.0384(6) ?, c = 12.8904(12) ?, β = 105.828(2)^o, P2₁ space group, Z = 2, d = 1.273 mg/m³.     

Stereoelectronic effects on cyclobutyl participation. The 10-tetracyclo[5.2.1.02,6.O3,9]decyl cation

While the solvolysis of tosylate 5c proceeds very rapidly to generate 4 or its rapidly equilibrating classical alternative, the epimeric compound 6c proved to be unreactive; bond orientation effects are implicated.     

Baseninduzierte umlagerungen von 3,9 dioxatricyclo[3.3.1.02,4]nonan-7-onen zu m-hydroxyphenylcarbonyl-verbindungen

8-Oxabicyclo[3.2.1]oct-6-en-3-ones (5), easily available by [4+3]cycloaddition, were epoxidised at the CC double bond. The 3,9-dioxatricyclo[3.3.1.0^2,4]nonan-7-ones (6) thus obtained are rearranged on treatment with sodium ethoxide in ethanol to form 3-hydroxybenzaldehydes (8a-d) and 3-hydroxy-2,4,5-trimethylacetophenone (8e) in good yields. As intermediates of these rearrangements, 8-hydroxy-6-oxatricyclo [3.2.1.0^2,7]octan-3-ones are postulated ; the trimethyl derivative 7g and the 6-carba-derivatives 4a,b could be isolated.     

Mechanism of the thermal conversion of tetracyclo[3.3.0.02,4.0.3,6]oct-7-ene into dihydropentalenes

One of a number of possible mechanisms has been established for the title reaction.     

Synthesis of tetracyclo[3.3.0.02.4.03.6]oct-7-ene and some of its derivatives

A full account is given of the synthesis of the title compound, its 7,8-dihydro-analogue and of some of its derivatives.