A Versatile Approach for Synthesis of 2,3-Dimethyl Chroman-4-ones, Intermediate for Calanolide Anti-HIV Agents,<i>VIA</i>Aldol/Mitsunobu Reactions
作者:Albert Khilevich、John D. Rizzo、Michael T. Flavin、Abram K. Sheinkman、Aye Mar、Alla Kucherenko、Changren Yan、Sergey Dzekhtser、Darko Brankovic、Lin Lin、Jinjun Liu、Thomas M. Rizzo、Ze-Qi Xu
DOI:10.1080/00397919608003792
日期:1996.10
Combined aldol/Mitsunobu reactions have been employed for the first time for synthesis of 2,3-dimethyl chroman-4-ones, intermediates for calanolide anti-HIV agents. Thus, the lithium enolate of chromene 1 reacted with acetaldehyde at -78 degrees C to afford the aldol products 4 and 5. Under Mitsunobu conditions (Ph(3)P/DEAD), the syn aldol product 4 led to the formation of trans-2,3-dimethyl chroman-4-one 2 while the anti aldol product 5 yielded both trans and cis derivatives (2 and 3). The use of other phosphorous and azo compounds in this reaction has also been investigated.