Blocking group, avoiding unnecessary

The initial preparation of dihydromancunine (Scheme 13) used an N -blocking group to avoid formation of vallesiachotamine derivatives (i.e. cyclization of C-17 onto iVb). Subsequently" it was found that a blocking group is unnecessary if more acidic media are used, but the yield is lower owing to denaturing of the enzyme used. In an extension of these studies to the 3a-H series strictosidine, treated with... 

Unnecessary derivatization (use of blocking groups, protection/de-protection, and temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste. 

Reduce derivatives—unnecessary derivatization (blocking groups, protection/deprotection/ temporary modification) should be avoided wherever possible. 

Avoid chemical derivatives avoid using unnecessary derivatization in the form of blocking or protect-ing-deprotecting groups or any temporary modification of physical or chemical processes. Derivatives consume additional reagents, thus, generating waste. 

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