Thianthrene as a source of the 1,2-benzene dianion
作者:Miguel Yus、Francisco Foubelo、José V. Ferrández
DOI:10.1016/s0040-4039(02)01661-1
日期:2002.9
Abstract The lithiation of thianthrene 1 with lithium and a catalytic amount of 4,4′-di- tert -butylbiphenyl (DTBB, 4% molar) in THF at −90°C, followed by reaction with a carbonyl compound [Bu t CHO, Me 2 CO, Et 2 CO, (CH 2 ) 5 CO] at the same temperature, gives an intermediate, which was lithitated again and reacted with a second carbonyl compound [Bu t CHO, PhCHO, Ph(CH 2 ) 2 CHO, Me 2 CO, Et 2 CO
摘要 噻蒽 1 与锂和催化量的 4,4'-二叔丁基联苯(DTBB,4% 摩尔)在 THF 中于 -90°C 进行锂化,然后与羰基化合物反应 [Bu t CHO, Me 2 CO、Et 2 CO、(CH 2 ) 5 CO] 在相同温度下得到中间体,将其再次锂化并与第二羰基化合物 [But CHO、PhCHO、Ph(CH 2 ) 2 CHO 反应, Me 2 CO、Et 2 CO、(CH 2 ) 5 CO]在最终水解后得到预期的二醇2。化合物 2 在酸性条件下(85% H 3 PO 4 )很容易环化,以几乎定量的产率产生预期的邻苯二甲酸酯。最后,当与第一种羰基化合物(PhCHO,Me 2 CO)反应后,使用二氧化碳作为第二种亲电试剂,经酸性处理后得到预期的取代苯酞3。
A Facile Synthesis of 1,3-Dihydro- isobenzofurans Using Iodocylization of 2-Vinylbenzyl Alcohols
An efficient route for the preparation of 1,3-dihydroisobenzofurans based on the iodine-mediated cyclization of 2-vinylbenzyl alcohols, which can be prepared feasibly by reactions of 2-vinylphenyllithiums with carbonyl compounds, is reported. Substitution reactions of the iodo moiety of the resulting 1-(iodomethyl)-1,3-dihydroisobenzofurans with tributyltin hydride and sodium thiolates are also described.
Convenient Synthesis of 1,3-Dihydroisobenzofurans by Hydriodic Acid-Catalyzed Cyclization of 2-Vinylbenzyl Alcohols
A new and short process has been developed for the preparation of 1,1,3-tri- and 1,1,3,3-tetra-substituted 1,3-dihydroisobenzofurans (phthalanes) from alpha-substituted 2-bromostyrenes. The method involves addition of a-substituted 2-lithiostyrenes, generated by the bromine-lithium exchange between alpha-substituted 2-bromostyrenes and butyllithium, to aliphatic aldehydes or ketones, followed by hydriodic acid catalyzed cyclization of the resulting 2-vinylbenzyl alcohols.
Selective halogen-lithium exchange in some secondary and tertiary (bromophenyl)alkyl halides
作者:William E. Parham、Charles K. Bradsher、David C. Reames
DOI:10.1021/jo00336a043
日期:1981.11
PARHAM, W. E.;BRADSHER, C. K.;REAMES, D. C., J. ORG. CHEM., 1981, 46, N 23, 4804-4806