Abstract A four-step synthesis of methyl 6-formyl-2-hydroxy-4-methoxy-3-(3-methylbut-2-en-1-yl)benzoate (11) that can be used as building block for a facilesynthesis of cajaninstilbene acid and its derivatives is reported. The synthesis of cajaninstilbene acid was accomplished in six steps with an overall yield of 20% starting from commercial materials by a synthesis whose key steps are TiCl4-mediated
Synthesis of dichloromethyl-substituted salicylates and pyran-4-ones by cyclocondensation of 1,3-bis(silyloxy)-1,3-butadienes with 1,1-dimethoxy-4,4-dichlorobut-1-en-3-one: control of the C,C- and C,O-regioselectivity by the choice of Lewis acid
The TiCl4-mediated formal [3+3] cyclocondensation of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 1,1-dimethoxy-4,4-dichlorobut-1-en-3-one afforded a variety of functionalized 6-dichloromethyl-4-methoxysalicylates with very good regioselectivity. Some of the products were transformed into 6-formyl-4-methoxysalicylates. The employment of Me3SiOTf instead of TiCl4 resulted in a change of the regioselectivity