299939-00-7

Upstream product

• 299938-96-8 (Z)-(2R,3R,5R,6R)-2,6-Bis-benzyloxy-5,7-bis-(tert-butyl-dimethyl-silanyloxy)-3-(4-methoxy-benzyloxy)-4,4-dimethyl-non-7-enal 
• 253663-00-2 (2R,3R,5R,6R)-2,6-bis(benzyloxy)-5-(tert-butyldimethylsiloxy)-8-chloro-3-(4-methoxybenzyloxy)-4,4-dimethyl-7-oxononanal 
• 100-39-0 benzyl bromide 
• 253662-96-3 (4R,5R,7R,8S)-4,8-bis(benzyloxy)-5,9-bis(t-butyldimethylsiloxy)-2,2-dichloro-7-(4-methoxybenzyloxy)-6,6-dimethylnonan-3-one 
• 253662-98-5 (4R,5R,7R,8S)-4,8-bis(benzyloxy)-5,9-bis(t-butyldimethylsiloxy)-2-chloro-7-(4-methoxybenzyloxy)-6,6-dimethylnonan-3-one 
• 333956-98-2 (4R,5R,7R,8S)-4,8-bis(benzyloxy)-5-(t-butyldimethylsiloxy)-2-chloro-9-hydroxy-7-(4-methoxybenzyloxy)-6,6-dimethylnonan-3-one 
• 253662-88-3 (2R,4R)-2-(4-methoxyphenyl)-5,5-dimethyl-4-[(1S)-1-benzyloxy-2-(t-butyldimethylsiloxy)ethyl]-1,3-dioxane 
• 253662-87-2 (1S)-1-[(2R,4R)-2-(4-methoxyphenyl)-5,5-dimethyl-1,3-dioxan-4-yl]ethane-1,2-diol 
• 333956-92-6 (2R,4R)-4-hydroxymethyl-2-(4-methoxyphenyl)-5,5-dimethyl-1,3-dioxane 
• 253662-80-5 (2R,4S)-2-(4-methoxyphenyl)-5,5-dimethyl-4-vinyl-1,3-dioxane 
• 253662-82-7 (2R,4R)-2-(4-methoxyphenyl)-5,5-dimethyl-1,3-dioxan-4-carbaldehyde 
• 599-04-2 (R)-Pantolacton 
• 163275-36-3 Methyl (2R,3R,5R,6S)-2,6-dibenzyloxy-3,7-bis(tert-butyldimethylsiloxy)-5-(p-methoxybenzyloxy)-4,4-dimethylheptanoate 
• 163275-35-2 Methyl (2R,3R,5R,6S)-2,6-dibenzyloxy-7-(tert-butyldimethylsiloxy)-3-hydroxy-5-(p-methoxybenzyloxy)-4,4-dimethylheptanoate 

Downstream Products

• 222726-89-8 (2R,3R,5R,6R,7R,8R)-7-Acetoxy-2,6-dibenzyloxy-3-(tert-butyldimethylsiloxy)-5-(p-methoxybenzyloxy)-4,4,8-trimethylcyclooctanone 
• 198711-88-5 (2R,3R,5R,6R,7S,8R)-7-Acetoxy-2,6-dibenzyloxy-3-(tert-butyldimethylsiloxy)-5-(p-methoxybenzyloxy)-4,4,8-trimethylcyclooctanone 

Relevant academic research and scientific papers

An effective method for the preparation of chiral polyoxy 8-membered ring enone corresponding to the B ring of taxol

An effective method for the preparation of 8-membered ring enone, (4S,5R,7R,8R)-4,8-bis(benzyloxy)-7-(t-butyldimethylsiloxy)-5- (4-methoxybenzyloxy)-2,6,6-trimethylcyclooct-2-enone (1), in sufficient quantities was developed. Optically active trioxy aldehyde, (3R,4S)-4-benzyloxy-5-(t-butyldimethylsiloxy)-3-(4-methoxybenzyloxy)- 2,2-dimethylpentanal (3), was prepared first by diastereoselective dihydroxylation of (2R,4S)-2-(4-methoxyphenyl)-5,5-dimethyl-4-vinyl-1,3-dioxane derived from D-pantolactone. Next, 8-chloro-7-oxoaldehyde, (2R,3R,5R,6R)-2,6-bis(benzyloxy)-5-(t-butyldimethylsiloxy)-8-chloro-3- (4-methoxybenzyloxy)-4,4-dimethyl-7-oxononanal (30), was newly synthesized by the following reactions: i) MgBr2·OEt2-mediated diastereoselective aldol reaction of the aldehyde 3 with (Z)-2-benzyloxy-1-methoxy-1-(trimethylsiloxy)ethene and ii) reaction of methyl (2R,3R,5R,6S)-2,6-bis(benzyloxy)-3,7-bis(t-butyldimethylsiloxy)-5- (4-methoxybenzyloxy)-4,4-dimethylheptanoate with 1,1-dichloroethyllithium, followed by successive reductive dehalogenation of thus formed 1,1-dichloroethyl ketone with 1,1-dichloroethyllithium. Then, the chiral 8-chloro-7-oxoaldehyde 30 was converted to the 8-membered ring enone 1 by SmI2-mediated aldol cyclization.

Fluoride ion-mediated intramolecular aldol cyclization of 7-(t-butyldimethylsiloxy)-7-octenal

Polyoxy 8-membered ring compound was synthesized in moderate to good yields by intramolecular aldol cyclization of 7-(t-butyldimethylsiloxy)-7-octenal using tetrabutylammonium fluoride (TBAF).