Aldolase-Catalyzed Synthesis of Conformationally ConstrainedIminocyclitols: Preparation of Polyhydroxylated Benzopyrrolizidinesand Cyclohexapyrrolizidines.

A straightforward chemo-enzymaticsynthesis of new polyhydroxylatedbenzopyrrolizidines and cyclohexapyrrolizidinesis developed. The two-step strategy consists of l-fuculose-1-phosphatealdolase variant F131A-catalyzed aldol addition of dihydroxyacetonephosphate to rac-N-benzyloxycarbonylindoline-2-carbaldehydeas well as (2S*,3aS*,7aS*)- and (2S*,3aR*,7aR*)-N-benzyloxycarbonyloctahydroindole-2-carbaldehydesand a subsequent one-step catalytic deprotection–reductiveamination. [ABSTRACT FROM AUTHOR]