| 摘要 |
<p>NEW MATERIAL:A compound expressed by formula I [A is carbamoyl or cyano; R<1> is H, (hydroxy)-lower alkyl or phenyl; R<2> is H or OH-protecting group; when either of R<3> and R<4> is H, the other is OR<2>; when R<3> is OR<2>, OR<2> at the 2'-position, together with OR<2> at the 3'-position, represents 2',3'-dihydroxy- protecting group; when R<4> is OR<2>, OR<2> at the 3'-position, together with OR<2> at the 5'-position, represents 3',5'-dihydroxy-protecting group]. EXAMPLE:5-Ethynyl-1-(2-deoxy-beta-D-ribofuranosyl)imidazole-4-carboxam ide. USE:A synthetic intermediate for antitumor agents having metabolic antagonistic action. PREPARATION:A compound expressed by formula II (X is halogen) is reacted with an acetylene derivative expressed by the formula HCidenticalCR<1>' [R<1>' is silyl, (hydroxy)-lower alkyl or phenyl]. If the group R<1>' is silyl group, removal of the silyl group is carried out and, as necessary, protecting groups are removed to afford the compound expressed by formula I (group A is cyano group).</p> |
