570397-58-9Relevant academic research and scientific papers
De novo formal synthesis of (-)-apicularen A via an iterative asymmetric hydration sequence
Li, Miaosheng,O'Doherty, George A.
, p. 6087 - 6090 (2007/10/03)
(Chemical Equation Presented) A de novo approach to the formal total synthesis of the macrolide natural product (-)-apicularen A has been achieved in 18 steps'from achiral starting materials. Both the absolute and relative stereochemistries of apicularen A were introduced by a Sharpless asymmetric dihydroxylation, a π-allyl-palladium catalyzed reduction, a stereoselective reduction, and a base-promoted transannulation to install the C-9 stereocenter.
Total synthesis of apicularen a through transannular pyran formation
Petri, Andreas F.,Bayer, Alexander,Maier, Martin E.
, p. 5821 - 5823 (2007/10/03)
A macrocyclization-transannulation strategy is the crux of an efficient total synthesis of the benzolactone enamide apicularen A (see scheme; Bn = benzyl). Key steps include a four-component coupling, a Stille cross-coupling to introduce the aromatic moiety, and the formation of the enamide from a hemiaminal. The size-selective macrolactonization of the ethoxyvinyl ester shown was followed by transannular etherification in excellent yield.
Applications of size-selective macrolactonizations to the synthesis of benzolactone-enamide core structures
Petri, Andreas F.,Kuehnert, Sven M.,Scheufler, Frank,Maier, Martin E.
, p. 940 - 955 (2007/10/03)
By utilizing Stille cross-coupling reactions four benzoic acid derivatives (18, 32, 46, 66) were prepared that carry a side chain with two secondary hydroxy groups. It could be shown that the hydroxy functions can be distinguished by size-selective macrolactonization reactions. Thus, 12-membered lactones 19 and 33 are favored over their 11-membered lactone counterparts 20 and 34, respectively, albeit with a low (60:40-70:30) ratio. The selectivity is much more pronounced if there is a competition between a 12- and 10-membered lactone. This could be shown with the two lactones 47 and 67. The 12-membered lactones 33, 47, and 67 represent core structures for analogs of the benzolactone enamides. The macrolactonization reactions were performed under Yamaguchi conditions.
