Simple syntheses of dihydrojasmone and cis-jasmone via 1,4-diketones

摘要: Two new routes for the synthesis of dihydrojasmone (10a) and cis-jasmone (10b)via 1,4-diketones (5a b) are described. For first route, pent-4-en-1-ol (1) was oxidised to corresponding aldehyde (2), which on reaction with suitable Grignard reagents gave olefinic alcohols (3a b). The former (3a) directly diketone (5a) by Jones reagent catalysed Hg-(OAc)2. latter (3b) stepwise, PCC give (4), then PdCl2 yield (5b). second pent-4-yn-1-ol (6) converted (7), using hydroxy-acetylenes (8a These were acetylenic ketones (9a b), in turn Hg2+ hydration Base cyclisation diketones yielded (10a respectively.