Synthesis, stereostructure, pyramidal inversion, and alkylation of 1-thioniabicyclo(4. 4. 0)decane salts

Journal Article · Wed May 23 00:00:00 EDT 1979 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00505a026· OSTI ID:5938779

Roush, D M; Price, E M; Templeton, L K; Templeton, D H; Heathcock, C H

Eastman's sulfonium salt, 1-thioniabicyclo(4.4.0)decane tetrafluoroborate, has been prepared by an improved process and shown to be an equimolar mixture (molecular compound) of trans and cis steroisomers 1a and 1b, each of which has been isolated in pure form. The 6-methoxycarbonyl analogue 9 has also been prepared. Stereostructures have been assigned by a combination of /sup 13/C NMR, 360-MHz /sup 1/H NMR, and single-crystal x-ray analysis of salt 9 (X/sup -/ = 1/sup -/). Crystals of 9 are monoclinic, space group P2/sub 1//n, a = 8.890 (3) A, b = 20.120 (7) A, c = 8.150 (3) A, ..beta.. = 110.17 (4)/sup 0/, Z = 4, t = 20/sup 0/C, R = 0.042 for 1432 x-ray reflections with F/sup 2/ > 2 sigma. Activation parameters for inversion of salt 1a are found to be ..delta..H/sup +/ = 28.0 +- 0.9 kcal mol/sup -1/ and ..delta..S/sup +/ = -3.8 +- 2.5 eu in the range 90.07 to 105.80/sup 0/C. Unstabilized sulfonium ylides were prepared and their interconversion by pyramidal inversion of sulfur has been investigated; activation parameters for the conversion were found to be ..delta..H/sup +/ = 20.5 kcal mol/sup -1/ and ..delta..S/sup +/ = 6 eu. Three of the four stereoisomeric 2-methyl-1-thioniabicyclo(4.4.0)decanes have been prepared and their sterostructures assigned by /sup 13/C NMR. Evidence is adduced that both ylides react with electrophiles in a stereoselective manner. Treatment of salt 1 with tert-butyllithium at -72/sup 0/C yields the corresponding ylide anions, which undergo stereoselective methylation to provide the 2,10-dimethyl-1-thioniabicyclo(4.4.0)decanes, stereostructures of which are assigned by /sup 13/C NMR. The ring fusion bond of 9 undergoes reductive cleavage, leading to an interesting synthesis of 6-methoxycarbonylthiacyclodecane.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 5938779
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 101:11; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ACETONE
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
BOND ANGLE
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DATA FORMS
DIFFRACTION
ENERGY
ENTHALPY
EXPERIMENTAL DATA
FURANS
HALOGENATED ALIPHATIC HYDROCARBONS
HETEROCYCLIC COMPOUNDS
HIGH TEMPERATURE
INFORMATION
IODINATED ALIPHATIC HYDROCARBONS
ISOLATED VALUES
ISOMERIZATION
ISOMERS
KETONES
LATTICE PARAMETERS
LITHIUM COMPOUNDS
LOW TEMPERATURE
MAGNETIC RESONANCE
MEDIUM TEMPERATURE
MOLECULAR STRUCTURE
MONOCLINIC LATTICES
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHYSICAL PROPERTIES
RESONANCE
SALTS
SCATTERING
STEREOCHEMISTRY
STRUCTURAL CHEMICAL ANALYSIS
SYNTHESIS
TEMPERATURE DEPENDENCE
THERMODYNAMIC PROPERTIES
X-RAY DIFFRACTION