Photochemistry of two .beta.,.beta.'-epoxy ketones, 3-oxatricyclo[3.2.1.02,4]octan-8-one and 3-oxatricyclo[3.3.1.02.4]nonan-9-one. Intramolecular reactions of .alpha.,.beta.-unsaturated aldehydo ketenes

Mechanistic studies on trans-2,3-dihydro-2,3-dihydroxybenzoate dehydrogenase (Ent A) in the biosynthesis of the iron chelator enterobactin

“…and {-)-trans-1,3-cyclohexadiene-5,6-diol (21) (Ganey et al, 1989); (±)-zrím-3-cyclohexene-1,2-diol (12) (Ross et al, 1982); 2,4-cyclohexadien-1 -ol (13) (Apparu & Barrelle, 1977); methyl (±)-2-acetoxy-3-hydroxy-6-cyclohexene-1-carboxylate (Quinn and Berchtold, manuscript in preparation); methyl (±)-( 1 a,5a,6a)-5-hydroxy-7-oxabicyclo[4.1,0]hept-3-ene-3carboxylate (Hoare et al, 1983;Pawlak & Berchtold, 1987); (±)-íra«j-3,4-dihydro-3,4-dihydroxy-1 -benzoic acid ( 16) (Ikota & Ganem, 1978; Padykula and Berchtold, unpublished results); methyl (±)-a>2-hydroxy-3-cyclohexene-1 -carboxylate (Ayral-Kaloustian et al, 1978); (±)-c/s-2-hydroxycyclohexane-1 -carboxylic acid (18) (Gabor et al, 1970); (±)ím/zs-2-hydroxycyclohexane-1 -carboxylic acid (19) (Yang & Dinesho, 1988); 3-oxo-l-cyclohexene-1-carboxlic acid (23) (Bugg et al, 1988); methyl (±)-2-oxocyclohexane-1carboxylate (Tsuda et al, 1986); methyl 2-oxo-3-cyclohexene-1-carboxylate (28) (Mander & Sethi, 1983); methyl 2-oxo-6-cyclohexene-1-carboxylate (29) (Liotta et al, 1981).…”

Absence of stereoelectronic control in the photochemistry of two diastereomeric .beta.,.gamma.-epoxy ketones

“…Irradiation of 34 (125 mg, 0.82 mmol) in methanolic benzene (50 mL) for 2 h 40 min (>95% conversion) gave two new products which were isolated by VPC on column A at 165 °C. The major product (68% recovered yield; retention time, 22 min) was characterized as 2-hydroxymethyi-2-cyclohexene-1 -acetic acid -lactone: IR 2925 (m), 2850 (w), 1750 (s, br), 1460 (w), 1440 (w), 1427 (w), 1370 (w, br), 1245 (w), 1220 (m), 1208 (w), 1170 (w), 1118 (w), 1082 (w), 1032 (m), 950 (w), 850 (w) cm"1; NMR (220 MHz) 5.67 (br s, fine structure, 1 ), 4.70 and 4.57 (m, AB q, fine splitting, Jab = 13.3 Hz, 2 H), 2.77-2.34 (m, 2 ), 1160 (m), 1120 (w), 1062 (w), 855 (w) cm"1; NMR (220 MHz) 9.68 (d, J = 2.6 Hz, 1 H),9.31 (s, 1 H), 6.79 (apparent t, J = 3.8 Hz, Irradiation of a small sample of 35 (8.5 mg) according to the above procedure gave the same two products as evidenced by VPC retention times and spectra of the isolated products. exo-and emfo-4-fezT-Butylbicyclo[4.2.0]oct-7-en-2-one Ethylene Ketals (24 and 25).…”

“…(1 R*,3S*,5R*,8R*)-3-ferf-Butylspiro[bicyclo[3.2.1]octane-8,2'oxlran]-6-one (5). Epoxide 36 (192 mg, 1.0 mmol) was added directly to a vigorously stirred suspension of mercuric acetate (320 mg, 1.0 mmol; Mallinckrodt) in water and acetonitrile (1.0 mL each).27 Stirring was continued for 32 h at room temperature.…”

Photochemistry of epoxyquinone. 5. Photoinduced cycloadditions of epoxynaphthoquinone to aldehydes, ketones, and oxygen

“…1972,94,3633. (10) In the HPLC chart, 1,3-dioxolanes 8c and 9c derived from the reaction of 3a with butyraldehyde eluted at 2.00 and 2.30 min, respectively, 3a at 2.60 min, and 1,3-dioxolanes 8i-m and 9i-m at later than 4 min.…”