194355-10-7

Upstream product

• 194355-09-4 (R)-6-((1R,2S)-1-Benzyloxy-2-hydroxy-2-phenyl-ethyl)-5,6-dihydro-pyran-2-one 
• 194355-07-2 (R)-6-((1R,2R)-1-Benzyloxy-2-hydroxy-2-phenyl-ethyl)-5,6-dihydro-pyran-2-one 
• 194355-04-9 Acetic acid (2R,3R)-2-[(1S,2R)-1-benzyloxy-2-(tert-butyl-dimethyl-silanyloxy)-2-phenyl-ethyl]-6-oxo-3,6-dihydro-2H-pyran-3-yl ester 
• 194355-08-3 4-Nitro-benzoic acid (1S,2S)-2-benzyloxy-2-((R)-6-oxo-3,6-dihydro-2H-pyran-2-yl)-1-phenyl-ethyl ester 
• 194355-05-0 (R)-6-[(1S,2R)-1-Benzyloxy-2-(tert-butyl-dimethyl-silanyloxy)-2-phenyl-ethyl]-3,6-dihydro-pyran-2-one 
• 194355-06-1 (R)-6-[(1S,2R)-1-Benzyloxy-2-(tert-butyl-dimethyl-silanyloxy)-2-phenyl-ethyl]-5,6-dihydro-pyran-2-one 
• 181534-66-7 (R)-5-[(1R,2R,3R)-2-Benzyloxy-3-(tert-butyl-dimethyl-silanyloxy)-3-phenyl-1-trimethylsilanyloxy-propyl]-5H-furan-2-one 
• 181534-68-9 (5R,6R)-6-[(1S,2R)-1-Benzyloxy-2-(tert-butyl-dimethyl-silanyloxy)-2-phenyl-ethyl]-5-hydroxy-5,6-dihydro-pyran-2-one 
• 153000-32-9 (R)-5-[(1R,2S,3R)-2-Benzyloxy-3-(tert-butyl-dimethyl-silanyloxy)-1-hydroxy-3-phenyl-propyl]-5H-furan-2-one 
• 146236-73-9 (+)-goniodiol 
• 519054-78-5 (2R,4R,5S,6S)-(5-benzyloxy-4-hydroxy-6-phenyltetrahydropyran-2-yl)thioacetic S-ethyl ester 

Downstream Products

• 136685-37-5 (1R,5R,7S,8S)-8-hydroxy-7-phenyl-2,6-dioxa-bicyclo-[3.3.1]-nonan-3-one 

Relevant academic research and scientific papers

Chiral hetero Diels-Alder products by enantioselective and diastereoselective zirconium catalysis. Scope, limitation, mechanism, and application to the concise synthesis of (+)-prelactone C and (+)-9-deoxygoniopypyrone

Catalytic asymmetric hetero Diels-Alder (HDA) reactions using a chiral zirconium complex have been developed. The reactions of aldehydes with Danishefsky's dienes proceeded smoothly to afford the corresponding pyranone derivatives in high yields with high diastereo- and enantioselectivities in the presence of a chiral zirconium complex, which was prepared from zirconium tert-butoxide, (R)-3,3′-diiodobinaphthol or its derivative, a primary alcohol, and a small amount of water. It is noted that 2,3-trans-pyranone derivatives were obtained with remarkably high diastereo- and enantioselectivities in the reaction with 4-methyl Danishefsky's diene. This is the first example of catalytic asymmetric trans-selective hetero Diels-Alder reactions of aldehydes. Furthermore, asymmetric HDA reactions with 4-benzyloxy Danishefsky's dienes were conducted to afford 2,3-cis-pyranone derivatives in high selectivities. Isolation of an intermediate of this asymmetric hetero Diels-Alder reaction indicated that the reaction proceeded in a stepwise cycloaddition pathway. Finally, these catalytic, asymmetric hetero Diels-Alder reactions were successfully applied to concise syntheses of biologically important natural pyranone derivatives, (+)-Prelactone C and (+)-9- deoxygoniopypyrone.

Stereoselective Syntheses of (+)-Goniotriol, (+)-8-Acetylgoniotriol, (+)-Goniodiol, (+)-9-Deoxygoniopypyrone, (+)-Altholactone, and (-)-Goniofupyrone

The γ-lactone intermediate (-)-7, derived from (+)-tricarbonyl(η6-o-(trimethylsilyl)benzaldehyde)chromium(0) complex, was efficiently converted into the corresponding δ-lactone intermediate (-)-11. This second intermediate has been shown to be a versatile compound for stereoselective syntheses of natural styryllactones possessing a six-membered lactone moiety, isolated from Goniothalamus giganteus, by transforming it into (+)-goniotriol, (+)-8-acetylgoniotriol, (+)-goniodiol, (+)-9-deoxygoniopypyrone, (+)-altholactone, and (-)-goniofupyrone.