Photochemistry of 5.6-epoxy-1,3-dienes

Photochemical reactions. 145th Communication. Carbonyl vs. epoxyketone photochemistry: Photolysis of 1,2;3,4‐diepoxy‐2,6,6‐trimethyl‐1‐cyclohexyl methyl ketone

“…) A transformation analogous to f i g -3 7 was previously observed on photolysis of the epoxydiene 38 furnishing 39 [31]. 1440~1, 1400m, 1385m, 1375m, 1365~1, 1340w, 1300m, 1275s (sh), 1270s, 1220w, 1205w, 1165w, 1145~1, 1105s, 1080~1, 1020m, 995m, 980s, 920s,900m, 890m, 865w.…”

Photochemical reactions. 144th Communication. Photochemistry of 5,6‐epoxy‐1,3‐dienes in the ionone series: Influence of a methoxy group in position 7

“…To assign the stereochemistry, (E/Z)-6 and (E/Z)-7 were correlated with the alcohols (E/Z)-20 and (E/Z)-21, respectively, which were obtained previously on photolysis of ( E ) -l [ 2 ] .…”

“…The structures and, in particular, the relative configuration at C(6) and C(7) of 12 and 13 was assigned by correlation with the alcohols 26 and 27 [2]. Thus, catalytic hydrogenation (Pd/BaS04) of 26 gave the double-bond isomer of the starting material (28) and, in addition, the two reduced diastereomeric products 29A and 29B6), presumably epimers at C(7).…”

“…Compound (E)-5 was obtained in 95% yield by reaction of (E)-1 [2] with NaH/Mel in DME. Yields are based on converted starting material.…”

“…Analogously, compound 24 was obtained by hydrogenation of (E/Z)-7 as well as by hydrogenation of (E/Z)-21 furnishing 25 [2], followed by reaction of the latter with Me,OBF,. Furthermore, 22 was cleaved by reaction with Me,SiI [8] leading to the alcohol 23 in moderate yield (22%).…”