217819-91-5

Upstream product

• 81577-69-7 [2R,4R,5R]-5-hydroxy-2-phenyl-[1,3]dioxane-4-carbaldehyde 
• 217819-88-0 (2R,4S,5R)-5-hydroxy-2-phenyl-m-dioxane-4-ethanol 
• 3006-41-5 4,6-O-benzylidene-D-glucose 
• 133782-90-8 (2R,4S,5R)-5-hydroxy-2-phenyl-4-vinyl-1,3-dioxane 
• 1125-88-8 benzaldehyde dimethyl acetal 
• 217819-89-1 (2R,4S,5R)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-ol 

Downstream Products

• 217820-03-6 (1S,2S,3R,4S)-1-<(E)-2-<(2R,4S,5S)-5-(benzyloxy)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-yl>vinyl>-3-(methoxymethoxy)-7,7-dimethyl-2-<(E)-1-propenyl>bicyclo<2.2.1>heptan-2-ol 
• 217820-04-7 (1S,2R,5R,6S,7E)-6-<(2R,4S,5S)-5-(benzyloxy)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-yl>-4-hydroxy-2-(methoxymethoxy)-5,11,11-trimethylbicyclo<6.2.1>undec-7-en-3-one 
• 217820-05-8 (1S,2R,5R,6S,7E)-6-<(2R,4S,5S)-5-(benzyloxy)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-yl>-2-(methoxymethoxy)-5,11,11-trimethylbicyclo<6.2.1>undec-7-ene-3,4-dione 
• 217820-02-5 (1S,3R,4S)-1-<(E)-2-<(2R,4S,5S)-5-(benzyloxy)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-yl>vinyl>-3-(methoxymethoxy)-7,7-dimethylbicyclo<2.2.1>heptan-2-one 
• 217820-06-9 (1S,2R,5R,6S,7E)-6-<(2R,4S,5S)-5-(benzyloxy)-4-(2-hydroxyethyl)-2-phenyl-m-dioxan-5-yl>-2-(methoxymethoxy)-5,11,11-trimethylbicyclo-<6.2.1>undec-7-ene-3,4-dione 
• 217820-01-4 (1S,3R,4S)-1-<(E)-2-<(2R,4S,5S)-5-(benzyloxy)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-yl>vinyl>-3-hydroxy-7,7-dimethylbicyclo<2.2.1>heptan-2-one 
• 217820-07-0 (2R,4S,5S)-5-(benzyloxy)-4-<(1E,3S,4R,7R,8S)-7-(methoxymethoxy)-4,11,11-trimethyl-5,6-dioxobicyclo-<6.2.1>undec-1-en-3-yl>-2-phenyl-m-dioxane-4-acetaldehyde 
• 217820-00-3 (1S,4R)-1-<(E)-2-<(2R,4S,5S)-5-(benzyloxy)-4-<2-(tert-butyldimethylsiloxy)ethyl>-2-phenyl-m-dioxan-5-yl>vinyl>-7,7-dimethylbicyclo<2.2.1>heptan-2-one 
• 217819-96-0 (2R,4S,5S)-4-<2-(tert-butyldimethylsiloxy)ethyl>-5-<(E)-2-<(1S,2R,4R)-2-hydroxy-7,7-dimethylbicyclo<2.2.1>hept-1-yl>vinyl>-2-phenyl-m-dioxan-5-ol 
• 217819-97-1 (1S,4R)-1-<(E)-2-<(2R,4S,5S)-4-<2-(tert-butyldimethylsiloxy)ethyl>-5-hydroxy-2-phenyl-m-dioxan-5-yl>vinyl>-7,7-dimethylbicyclo<2.2.1>heptan-2-one 

Relevant academic research and scientific papers

Stereochemical models for the enantiocontrolled construction of fully functionalized C rings via intramolecular aldolization in advanced precursors to paclitaxel

Six transition-state models for intramolecular aldol C-ring annulation in suitably substituted bicyclo-[6.2.1]undecanones have been defined. The first consideration is the inherent conformational flexibility of the nine- membered ketonic ring which does not limit effective deprotonation to a single C-8 epimer. When the oxygen substituents at C-4 and C-5 are not covalently linked, the configuration at C-5 defines the stereochemical course of the ring closure, with only the β series being amenable to the proper elaboration of paclitaxel. When C-4 and C-5 are incorporated into a 1,3- dioxane ring instead, the principal stereocontrol element is translocated into the aryl-substituted carbon of the cyclic acetal. To the extent that the Ar group remains equatorially disposed, then proper aldolization will materialize in only one of the four possible diastereomers. Experimental tests that are provided for three of the models are shown to conform to expectations. This analysis of the origin of stereoselectivity has, for the first time, defined the scope and limitations associated with C-ring closure by means of the aldol protocol.