| abstract |
The present invention relates to compounds of formula (I) in which R 1 is selected from C 1-6 -alkyl, C 3-6 -cycloalkyl and aralkyl, R 2 is independently at each occurrence halogen or C 1 -6 -alkyl, m is an integer from 0 to 4, Q is selected from halogen, -NO 2 and -NR 3 R 4 , R 3 and R 4 are independently hydrogen, C 1- Selected from 6 -alkyl, C 3-6 -cycloalkyl, aryl, aralkyl, mesyl and tosyl, or R 3 and R 4 together form a C 4-6 -alkylene group, Y is each occurrence Or a hydroxy protecting group W that can be hydrolytically cleaved under acidic conditions, and n is an integer from 1 to 3, provided that n and m together are not greater than 5. . [Chemical 1] [Selection figure] None |