| Summary: | 碩士 === 國立交通大學 === 應用化學系 === 82 === In order to study the effect of various hetero-substituents at
the 5th position of the furan ring on the intramolecular Diels-
Alder reaction, the furfuryl propargyl ethers with
methylsulfinyl , methylsulfonyl, phenylthio and trimethylsilyl
group at the 5th position of the furan ring were prepared for
the cycloaddion. Thus, intramolecular Diels-Alder reaction of
(9)-(13) with t-BuOK in t-BuOH gave the methylsulfinyl group
1,2-rearranged products (14)-(18) respectively. Intramolecular
Diels-Alder reaction ofmethylsulfonyl compounds (20)-(24) under
the same reaction condition gave the 1,2-rearranged products
(25)-(29) respectively .In the case of compound (21), a small
amount of by product (26b) with the sulfonyl group completely
leaving was isolated. Intramolecular Diels-Alder reaction of
the phenylthio compounds (32-1),(33-1)and(34) under the same
reaction conditions gave both the 1,2-rearranged products
(35a)-(37a) and the 1,4-rearranged products (35b)-(37b)
respectively. Intramolecular Diels-Alder reaction of the
trimethylsilyl compounds (44-1) and (45-1) under the same
reaction conditions gave the 1,2-rearranged products (46a) and
(47), and the Brook's anionic rearrangement product (46b),
Futher studies on this reaction will be continued in our lab..
Thus, we found that different functional group at the 5th
position of the furan ring gave different rearrangement
products during the intramolecular Diels-Alder reaction.
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