Sodium cyanoborohydride inhibitor

Piperidine synthesis.3 The important glycohydrolase inhibitor 1-deoxynojiri-mycin (3) can be prepared in two steps from 5-keto-D-glucose (1). Thus 1 on treatment with benzhydrylamine and sodium cyanoborohydride in CH3OH at 0° undergoes double reductive amination to form essentially only one product (2), which on deprotection provides the piperidine 3. The high stereoselectivity is attributed to hydroxyl-directed hydride delivery. 

The racemic cyclopentenone (17), obtained as a byproduct in a synthesis of neplanocin A, has been used to make ( )-neplanocin F (18). A similar starting material has been used to make 3-deaza-neplanocin A (19), which shows antiviral properties and is a power-ful inhibitor of S-adenosyl-homocysteine hydrolase. This enzyme has been used to oxidize neplanocin A to the corresponding 3 -keto analogue sodium cyanoborohydride reduction of this ketone was... 

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