Reduction of DDHQ and TCC esters by NaBH4-its specificity in the presence of Alkyl/Aryl esters
作者:Tirumalai R. Kasturi、Palle V.P. Pragnacharyulu
DOI:10.1016/s0040-4020(01)80451-8
日期:1992.1
DDHQ/TCC esters 3a–f, 7a–g were prepared either by oxidation of spiroketones 1 with DDQ/-chloranil or by condensation of acid chloride with DDHQ/TCC. NaBH4 reduction of unsaturated DDHQ 3a–b and TCC 7a–c esters gave the corresponding allylic alcohols in good yield without any observable 1,4-addition products. Reduction of saturated esters 3e, 7d, gave the corresponding alcohols. Alkyl esters 5 and 6
DDHQ / TCC酯3a-f,7a-g可以通过用DDQ /-邻苯二甲酰氧化螺酮1或将酰氯与DDHQ / TCC缩合来制备。用NaBH 4还原不饱和DDHQ 3a-b和TCC 7a-c酯可得到相应的烯丙基醇,收率很好,没有任何可观察到的1,4-加成产物。还原饱和酯3e,7d,得到相应的醇。在这些还原条件下,烷基酯5和6,苯甲酸甲酯和苯甲酸苯酯不受影响。在化合物7e的还原中同时含有烷基酯和TCC酯的TCC酯被选择性还原。还原TCC单酯7f-g得到内酯。观察到的减少量已经合理化。