5-methoxy and 5-phenoxy-2 3A5-tetramehtylcyclopent 2-enone as synthetic equivalents for 2,3,4,5-tetramethylcyclopentadienone, 1990

Collection:
Atlanta University and Clark Atlanta University Theses and Dissertations
Title:
5-methoxy and 5-phenoxy-2 3A5-tetramehtylcyclopent 2-enone as synthetic equivalents for 2,3,4,5-tetramethylcyclopentadienone, 1990
Creator:
Castro, Alfredo
Contributor to Resource:
Mintz, Eric A.
Date of Original:
1990-08-01
Subject:
Degrees, Academic
Dissertations, Academic
Location:
United States, Georgia, Fulton County, Atlanta, 33.749, -84.38798
Medium:
dissertations
theses
Type:
Text
Format:
application/pdf
Description:
Degree Type: thesis
Degree Name: Master of Science (MS)
Date of Degree: 1990
Granting Institution: Clark Atlanta University
Department/ School: Department of Chemistry
Treatment of 2,3,4,5-tetramethylcyclopent-2-enone enolate, 15, with Br2 at -78 �C gave, upon work up, 5-bromo-2,3,4,5-tetramethylcyclopent-2-enone, 20, in 97 % yield. Treatment of 20 with KOCH3/CH3OH gave 5-methoxy-2,3,4,5-tetramethylcyclo- pent-2-enone, 22b, in 85 % yield. In an analogous manner treatment of 20 with KOC6H5 in CH3OH or THE gave 5-phenoxy-2,3,4,5-tetramethylcyclopent-2-enone, 30b, in 80% yield. Treatment of 22b and 30b with methylmagnesium bromide or methyllithium followed by acidic work up gave 1,2,3,4-tetramethylfulvene, 33, in high yield. Treatment of 30b with ethylmagnesium bromide gave, upon acidic work up, a 5 to 1 mixture of 1,2,3,4,6-pentamethyl-fulvene, 8, and vinyltetramethylcyclopentadiene, 9. Treatment of 22b with cyclopentylmagnesium chloride or cyclohexylmagnesium chloride gave, upon acidic work up, 6,6-tetramthylene-1,2,3,4-tetramethylfulvene, 34, and 6,6-pentamethylene-1,2,3,4-tetramethylfulvene, 36, in good yield. Finally, treatment of 30b with isopropylmagnesium chloride gave, upon acidic work up, a 10 to 1 mixture of isopropenyltetramethylcyclopentadiene, 38, and 6,6-dimethyl-1,2,3,4-tetramethyl�fulvene, 39, in good yield. Addition of lithium triethylborohydride or lithium aluminum hydride to 36, led to only incomplete transformation to 1-cyclohexyl-2,3,4,5-tetramethylcyclopentadiene, 40, however an authentic sample was prepared in good yield by treatment of 7 with cyclohexylmagnesium chloride in ether followed by acidic work up. Addition of indenyllithium or fluorenyllithium to 8 followed by hydrolysis gave upon work up l-(l-indenyl)(2,3,4,5-tetramethylcyclopentadienyl)ethane, 42, and l-(l-fluorenyl)(2,3,4,5-tetramethylcyclopentadienyl)ethane, 44, in low yield.
Metadata URL:
http://hdl.handle.net/20.500.12322/cau.td:1990_castro_alfredo
Language:
eng
Holding Institution:
Clark Atlanta University
Rights:

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