Novel reduction (Zn-AcOH) of DDHQ esters. A new route to tropone synthesis
作者:Tirumalai R. Kasturi、Pragnacharyulu V.P. Palle、Jitendra A. Sattigeri、Kaipenchery A. Kumar
DOI:10.1016/0040-4020(95)01006-8
日期:1996.1
Zn/acetic acid reaction of DDHQ esters 1 a–d gave the saturated acids 3 a–d and the hydrocarbons 7 a–d. The intermediacy of the aldehydes 10 and 11 in the formation of the products has been established. Oxidation of hydrocarbons 7a and 7b gave the corresponding tropones (5a and 5b).
Oxidation of spiroketones with DDQ - synthesis of tropone derivatives and DDHQ diesters
作者:Tirumalai R. Kasturi、Palle V.P. Pragnacharyulu、Gouravaram M. Reddy、Srirangam K. Jayaram、Sheo B. Singh
DOI:10.1016/s0040-4020(01)88302-2
日期:1992.1
derivatives 4a–f and DDHQ esters 5a–f (- isomer 6a–f, - isomer 7a–f). While the aryl substituted spirokeone 17a gave a 2:1 mixture of 19a and the corresponding - isomer, the aryl substituted spiroketones 17b–d gave exclusively - isomers 19b–d. Heating acid chloride of acid 9c with DDHQ resulted in compounds 4a and 7a, thus confirming the structuresassigned. Mechanism of formation of these compounds
用干苯中的DDQ氧化螺酮3a-f,得到托克酮衍生物4a-f和DDHQ酯5a-f(-异构体6a-f,-异构体7a-f)。而芳基取代spirokeone 17A给予了2:1混合物19A相应的和-异构体,所述芳基取代的spiroketones 17B-d仅仅得到-异构体19B-d 。用DDHQ加热酸9c的酰氯得到化合物4a和7a,从而确认分配的结构。这些化合物的形成机理已经合理化。对化合物7d的2D 1 H- 1 H COSY,1 H- 13 C COSY,HMBC和2D NOESY的详细研究导致1 H和13 C NMR信号及其溶液构象的完全分配。