(Production and reactions of substituted dihydrofurans and thiophenes). [Cyclooctadecane]

Technical Report · Mon Jun 01 00:00:00 EDT 1987

OSTI ID:6227939

Huang, Y J

Results of Section I not only unambiguously support the previous proposed two-step mechanism for the dimerization of 2,3-dimethylene-2,3-dihydrofuran (1), they also provide two of the most unreactive o-quinodimethanes, namely, 2-methylene-3-t-butylmethylene-2,3-dihydrofuran (2) and 2,3-di-t-butylmethylene-2,3-dihydrofuran. In Section II, the preparation and the dimerization of a series of alkyl ring-substituted and carbomethoxy ring-substituted derivatives of 1 are presented. This study concludes that bulky alkyl substituents on the ring of furan monomers do not promote the (4+2) dimerization process. In Section III, a Diels-Alder reaction of 1 and its two deuterated analogues with methyl acrylate reveals the presence of a secondary deuterium isotope effect which strongly supports a stepwise mechanism. This conclusion is further strengthened by the fact that the Diels-Alder reaction of 1 with cis dienophiles proceeds non-stereo-specifically. A comparison study of o-xylylene with dienophiles reaches the same conclusion. Section IV presents a convenient synthesis of cyclooctadecane from the thiophene trimer of 2,5-dimethylene-2,5-dihydrothiophene.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6227939
• Report Number(s): IS-T-1292; ON: DE87011254
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CYCLOALKANES
DIELS-ALDER REACTION
DIMERIZATION
FURANS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
POLYMERIZATION
SYNTHESIS
USES
YIELDS