Diversification of<i>ortho</i>-Fused Cycloocta-2,5-dien-1-one Cores and Eight- to Six-Ring Conversion by σ Bond C−C Cleavage
作者:Lee Eccleshare、Leticia Lozada-Rodríguez、Phillippa Cooper、Laurence Burroughs、John Ritchie、William Lewis、Simon Woodward
DOI:10.1002/chem.201601970
日期:2016.8.22
S2Me2, CO2 and lead to the expected C‐E derivatives (E=H, D, I, allyl, SMe, CO2H) in 49–64 % yield directly from intermediate 5. The parents (E=H; R1=SiMe3, tBu; R2=Ph) are versatile starting materials for NaBH4 and Grignard C=O additions, desilylation (when R1=SiMe) and oxime formation. The latter allows formation of 6,9‐bicyclics via Beckmann rearrangement. The 6,8‐ring iodides are suitable Suzuki
的2-C顺序处理6 ħ 4能Br(CHO)与LiC≡CR 1(R 1 =森达3,吨丁基),Ñ丁基锂,CuBr⋅SMe 2和HC≡CCHClR 2 [R 2 =苯基,4-CF 3 PH,3- CNPH,4-(MEO 2 C)PH]在-50℃下导致形成的中间碳负离子(的ž)-1,2--C 6 H ^ 4 C阿(= O)C≡C乙- [R 1 } CH = CH(CH -)R 2 }(4)。低温(−50°C)有利于C B的侵蚀导致6,8个自行车的动力学形成,其中包含非经典的C-碳双烯酸烯醇化物(5)。较高的温度(相对于环境温度为−10°C)和缺乏电子的R 2有利于逆向σ键C-C裂解再生4,其随后在C A上关闭,提供6,6-双环醇盐(6)。计算模型(CBS-QB3)表明这两种途径都是可行的,并且具有相似的能量。6与H +反应生成1,2-二氢萘-1-醇,或在脱水条件下生成2-芳基-1-炔基萘。烯醇盐5与以下物质原位反应:H