反応 #81580
ord-a5565d1da3264acfbba9e85fea2d9eaa
反応方程式
反応物
試薬
反応条件
後処理
- 1その他Reaction Scheme 2
- 2その他serves as a starting material for the synthesis of several preferred compounds of the invention
実験手順
In the preferred compounds of the invention the two R1 substituents are methyl, and the R2 and R3 substituents are hydrogen. Reaction Scheme 2 illustrates a synthetic process for preparing 7-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1-one (Compound G) which serves as a starting material for the synthesis of several preferred compounds of the invention. Thus, referring now specifically to Reaction Scheme 2, ethyl 3-bromophenylacetate (Compound B, made by esterification of 3-bromophenylacetic acid) is reduced with diisobutylaluminum hydride (DIBAL-H) to yield (3-bromophenyl)acetaldehyde. (3-Bromophenyl)acetaldehyde is reacted in a Wittig reaction with (carbethoxymethylene)triphenylphosphorane to provide a mixture of E and Z ethyl 4-(3-bromophenyl)but-2-enoates. The latter compounds are hydrogenated to yield ethyl 4-(3-bromophenyl)butanoate (Compound D). Compound D is reacted with the Grignard reagent derived from methylbromide to give the tertiary alcohol 5-(3-bromophenyl)-2-methylpentan-2-ol (Compound E) (It should be apparent to those skilled in the art, that the choice of the Grignard reagent used in this reaction step determines the nature of the R1 substituent in the resulting compounds of the invention.) Compound E is then treated with acid to cyclize it and to form 6-bromo-1,2,3,4-tetrahydro-1,1-dimethylnaphthalene (Compound F). Compound F is oxidized with chromium trioxide to yield 7-bromo-3,4-dihydro-4,4-dimethylnaphthalen-1(2H)-one (Compound G). Compound G is covered by Formula 10 and in accordance with Reaction Scheme 1 serves as a starting material in the synthesis of several preferred compounds of the invention.