Abstract
The photocycladdition reaction of the dioxopyrroline 1 to cyclic trimethylsilyloxy olefins was examined. The addition of 3-trimethylsilyloxy-lH-indene and 4-trimethylsilyloxy-l,2-dihydronaphthalene occurred in a regio- and stereoselective manner to give the cis-anti-cis cyclobutanes 3 and 4, respectively. The stereochemical result supported the stereo-selection rule which states that the photocycloaddition of a very polar dioxopyrroline-olefin pair proceeds in an s + s manner via a favored O-endo-π-complex transition. On the other hand, the addition of 1-trimethylsilyloxycyclopentene and l-trimethylsily!oxycyclohexene occurred less stereoselectively, proceeding predominantly in an s + a manner to give the adducts 5a, b, 6a, b, 7a, b, and 12. The results are consistent with the prediction of the stereo-selection rule obtained by assuming that these dioxopyrroline-olefin pairs are polar. The latter cases demonstrate that an increased steric hindrance around the olefin moiety affects the polarity of enone-olefin pair in the transition state.
Original language | English |
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Pages (from-to) | 64-72 |
Number of pages | 9 |
Journal | Chemical and Pharmaceutical Bulletin |
Volume | 41 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1993 Jan 1 |
Externally published | Yes |
Keywords
- X-ray analysis
- cyclobutane
- dioxopyrroline
- donor-acceptor interaction
- photocycloaddition
- stereochemistry
ASJC Scopus subject areas
- Chemistry(all)
- Drug Discovery