for the following products
Boc-Asn(Xan)-OH | Boc-L-Asn(Xan)-OH | N-alpha-tert-Boc-N-beta-xanthyl-L-asparagine | N-alpha-tert-Butyloxycarbonyl-L-N-beta-xantyl-asparagine | N-alpha-tert-Butyloxycarbonyl-N-beta-xantyl-L-asparagine and N-Boc-N'-Xanthyl-L-asparagine
