5'-alkynylation of uridine-derived aldehydes is described. The addition of alkynyl Grignard reagents on the carbonyl group is significantly influenced by the 2',3'-di-O-protecting groups (R1): O-alkyl groups led to modest diastereoselectivities (65:35) in favor of the 5'R-isomer, whereas O-silyl groups promoted higher diastereoselectivities (up to 99:1) in favor of the 5'S-isomer. A study related to this
描述了
尿苷衍生的醛的5'-炔基化。炔基
格氏试剂在羰基上的添加受到2',3'-di-O-保护基(R1)的显着影响:O-烷基导致适度的非对映选择性(65:35),有利于5' R-异构体,而O-甲
硅烷基则促进了更高的非对映选择性(最高达99:1),有利于5'S-异构体。报道了有关该保护基对非对映选择性的影响的研究。