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Diastereomeric photoreaction solid state

Sakamoto et al. also demonstrated an absolute oxetane synthesis in the solid-state photolysis of Y-( ,(3-unsaturatcd carbonyl)benzoylformamides 43. [28] The X-ray analysis of Y-isopropyl substituted imide 43a revealed that the crystal system was monoclinic and the space group P2. Crystals of 43a were powdered and photolyzed at 0°C. The imide undergoes the [2+2] cycloaddition to afford the bicyclic oxetane 44a, which is a mixture of diastereomers, namely, syn- and anh-isomers at the C-7 position. In this reaction optically active. syn-oxctanc 44a with 37% ee (84% chemical yield) and racemic anti-44a were obtained. The solid-state photoreaction proceeded even at -78°C, and optically active syn-44n which showed ee value as high as >95% ee, (conv 100%, chemical yield 89%) was formed in a higher diastereomeric ratio (syn/anti = 6.5). Under identical conditions A-bcnzyl substituted 43b was irradiated in the solid state. [Pg.114]


See other pages where Diastereomeric photoreaction solid state is mentioned: [Pg.2]    [Pg.234]    [Pg.442]    [Pg.479]    [Pg.489]    [Pg.442]    [Pg.479]    [Pg.489]    [Pg.371]    [Pg.563]    [Pg.563]   
See also in sourсe #XX -- [ Pg.492 ]




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