Further Insight into ‘Matching’ of Donors and Acceptors via Reciprocal ­Donor Acceptor Selectivity (RDAS) Studies

Abstract

Experiments with n-pentenyl glycosides and thioglycosides show that protecting groups have a dominant effect in controlling regioselective glycosidations whereby the best ‘match’ of donor with acceptor emerges. The experiments also show that for this outcome to be observed, the armed and disarmed donors must be allowed to compete on an equal level. If this condition is not met, coupling may still occur, but it will not be the best ‘match’.

Key words

n-pentenyl glycosides - thioglycosides - regioselective glycosylations - armed glycosyl donors - disarmed glycosyl donors

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18

The trichloroacetimidates behaved differently from their NPG and thioglycoside counterparts in the three component glycosidations. An explanation for this observation is currently being sought.