Disarmed, moderately

SCHEME 37. Sequential activation of armed —> moderately disarmed — disarmed building blocks 185, 186,188, respectively.169... 

Consequently Demchenko has described 61 as moderately disarmed, and 62 as disarmed. The prosecution of this concept invites fiirther scrutiny. 

For the synthesis of (2-9) dimer, armed thiosialoside donor 37 was coupled with disarmed thiosialoside acceptor 41 which bears the common acetamido group at C-5. The resulting disaccharide 42 was obtained in moderate yield and stereoselectivity. Interestingly, the arming and disarming of these building blocks was achieved from a remote position. 

The discovered cooperative effect was then applied to convergent synthesis of a variety of differently linked oligosaccharides (69). Amongst those, the activation of the armed 42 over a moderately (dis)armed 47 in the presence of Cu(0Tf)2 provided the disaccharide 48 in 64 % yield (Scheme 13). Subsequently, compound 48 was activated over a disarmed glycosyl acceptor 49... 

Technology enables unguarded areas to become virtually impossible to enter undetected. Even moderately sophisticated security systems cannot be disabled or disarmed without sending out an alarm. All openings to the property can be protected. Even fences can be... 

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