Generation and Synthetic Application of Metallated Methyl Isopropenyl Ether, A Substitute for Acetone Enolate
作者:Foroogh Taherirastgar、Lambert Brandsma
DOI:10.1002/cber.19971300107
日期:1997.1
Methylisopropenylether (1) has been metallated at low temperature with a 1:1 molar mixture of n-BuLi/t-BuOK in THF-hexane, and subsequently functionalized with a variety of electrophilic reagents. At temperatures higher than – 30°C, the metallatedmethylisopropenylether (2) decomposes with formation of allene. When the suspension of 2 is allowed to warm up to room temperature in the presence of
甲基异丙烯基醚(1)已在低温下以1:1摩尔n -BuLi / t -BuOK在THF-己烷中的混合物进行了金属化处理,随后用各种亲电试剂进行了功能化。在高于– 30°C的温度下,金属化的甲基异丙烯基醚(2)分解并形成丙二烯。当在额外的当量正丁基锂存在下让2的悬浮液升温至室温时,中间的丙二烯转化为1-丙炔基锂(2c),后者与硫氰酸丙酯反应生成1-丙硫基-1-丙炔(4)。对某些官能化产物进行酸性水解,得到预期的甲基酮。
A radical cyclisation based cyclopentenone annulation of allyl alcohols
作者:A. Srikrishna、R. Viswajanani、J.A. Sattigeri
DOI:10.1016/s0957-4166(03)00535-4
日期:2003.10
A four-step cyclopentenone annulation reaction of allylic alcohols employing a 5-exo-trig radical cyclisation reaction of mixed allyl methyl ketals of bromoacetone as the key step is described. The annulated product 1215 obtained from 2.3-dimethylcyclohexenol has been further elaborated into (+/-)-epibakkenolides employing a 5-exo-dig radical cylisation reaction based alpha-spiro-beta-methvlene-gamma-butyrolactone annulation methodology. (C) 2003 Elsevier Ltd. All rights reserved.