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Chemoenzymatische „Chiral‐Pool”︁‐Synthese von (+)‐ exo ‐Brevicomin aus Kohlenhydraten mit Fructose‐1,6‐diphosphat‐Aldolase
Author(s) -
Schultz Michael,
Waldmann Herbert,
Kunz Horst,
Vogt Walter
Publication year - 1990
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.1990199001184
Subject(s) - aldol reaction , chemistry , tributyltin hydride , aldolase a , bicyclic molecule , stereochemistry , adduct , ketone , fructose bisphosphate aldolase , diol , medicinal chemistry , organic chemistry , enzyme , catalysis
Chemoenzymatic “Chiral‐Pool” Synthesis of (+)‐ exo ‐Brevicomin from Carbohydrates Using Fructose 1,6‐Diphosphate Aldolase Fructose‐1,6‐diphosphate aldolase (EC 4.1.2.13) catalyzes the stereospecific aldol reaction between 1,3‐dihydroxyacetone phosphate ( 4 ) and 5‐oxohexanal ( 3 ) or its 5‐dithiane‐protected analog 8 . The products of the aldol reactions are dephosphorylated with acid phosphatase (EC 3.1.3.2). Whereas the aldol adduct of 3 cyclizes spontaneously to give the bicyclic brevicomin precursor 3 , the adduct of 8 first has to be deprotected with sulfuryl chloride and wet silica gel. The resulting bicyclic α‐hydroxy ketone 3 is reduced with LiAlH 4 to form the 1,2‐diol 14 which is then deoxygenated to give the vinyl compound 17 by treatment of the corresponding dixanthate 15 with tributyltin hydride or by treatment of the corresponding mesylate 16 with sodium naphthalenide. The olefin 17 is finally converted to (+)‐ exo ‐brevicomin ( 1 ) by hydrogenation with diimide.