| 摘要 |
There are described a process for the preparation of a compound of the formula <CHEM> wherein R is unsubstituted or substituted C1-C12alkyl, C2-C4alkenyl, C2-C4alkynyl, C3-C6cycloalkyl, aryl, heteroaryl or -SR1; R1 is unsubstituted or substituted C1-C12alkyl, C1-C4alkenyl, C2-C4alkenyl, C2-C4alkynyl, cycloalkyl, aryl or heteroaryl; and X is a leaving group; which comprises a) reacting a compound of the formula <CHEM> wherein R is as defined above, with a water-removing agent; or b) for the preparation of a compound (I) wherein X is halogen or a sulfonate, reacting a compound of the formula <CHEM> wherein R is as defined for formula (I), with a halogenating agent or a sulfonylating agent; or c) for the preparation of a compound (I) wherein X is halogen, reacting a compound <CHEM> wherein R is as defined for formula (I); and R2 and R3 are for example, H, C1-C6alkyl, C3-C6cycloalkyl, phenyl or benzyl; with a compound of the formula halogen-C(=O)-O-C1-C8alkyl, halogen-C(=O)-O-aryl or halogen-C(=O)-O-benzyl; intermediates for the preparation of the compounds (II) to (IV) and (VI) and a method for the preparation thereof. |
