Application of Cyclopropenes in the Synthesis of Homochiral Cyclopropanes

Tez Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: University of Wales, Bangor, Kimya, Birleşik Krallık

Tez Danışmanı: Prof. Dr. Mark S. Baird

Tezin Onay Tarihi: 1996

Tezin Dili: İngilizce

Desteklendiği Program: YÖK 100/2000 Programı

Özet:

The reaction of 2,3-O-isopropylidene-D-glyceraldehyde-N-benzylimine with various lithiocyclopropene were investigated. The product cyclopropene amines (A, R = Me. n-Bu) were obtained in good diastereopurity. Reaction of (A, R = Me) with t-BuOK gave separable isomers of N-Benzyl 1-(2-methylenecyclopro-1-yl)-2-(3,3-dimethyl-2,4-dioxacyclopent-1-yl)methan-amine. Reaction with LDA gave substituted butadiene derivatives (B).

Reaction of 1,1,2-trihalocyclopropane carboxaldehyde with various diols leads to the protected cyclopropanes (C, X = Br, Cl ; R = H, Me, CH2OBr). The homochiral cyclopropanes are obtained as two diastereomers in ratio 1:1.

1,2-Dehalogenation of 1,1,2-trihalocyclopropanes by reaction with one mol. equiv. of methyllithium leads to single homochiral 1-halocyclopropenes, which then react with a second equiv. of methyllithium to give lithiocyclopropenes, The latter could be trapped by different nucleophiles and electrophiles. In this project cyclopropanes of type (D, Y = H, Br) and cyclopropenes of type (E, R = R' = Me ; R = t-Bu, R' = H ; R = t-Bu, R' = Me) were prepared.