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Photochemical Generation And Intramolecular Chemistry Of 2-Hydroxy-2-Methylpropylidene, Robin Farlow

Honors Theses

2-(1a,9b-Dihydro-lH-cyclopropa[l]phenanthren-1-yl)-propan-2-ol was synthesized by two different but related synthetic routes and characterized by melting point, IR GC/MS, CHN, and NMR spectroscopy. Photolysis of the alcohol in benzene d-6 led to the formation of 2-butanone, 1-methylcyclopropanol, and 2,2-dimethyloxirane in a 26:10:1 ratio via 2-hydroxy-2methylpropylidene, a novel ?-hydroxycarbene. These products are a consequence of intramolecular insertions of the carbene into C-C, C-H, and O-H bonds. Molecular orbital calculations performed at the Becke-3LYP/6-31G(d) level indicate that the singlet form of this carbene is more thermodynamically stable than the triplet. Furthermore, the transition states to the three products from the singlet species were modeled …