113094-29-4

Upstream product

• 40662-79-1 (2,6-di-t-butyl)-phenyl propanoate 
• 78-84-2 isobutyraldehyde 

Downstream Products

• 120483-23-0 (S)-4-Hydroxy-1-((2S,5R,6S)-6-isopropyl-2-methoxy-5-methyl-tetrahydro-pyran-2-yl)-6-(toluene-4-sulfonyl)-hexan-2-one 
• 120483-23-0 (R)-4-Hydroxy-1-((2S,5R,6S)-6-isopropyl-2-methoxy-5-methyl-tetrahydro-pyran-2-yl)-6-(toluene-4-sulfonyl)-hexan-2-one 
• 120483-10-5 (2S,6R,8R,9S)-8-Isopropyl-9-methyl-2-[2-(toluene-4-sulfonyl)-ethyl]-1,7-dioxa-spiro[5.5]undecan-4-one 
• 120483-11-6 (2S,4S,6R,8R,9S)-8-Isopropyl-9-methyl-2-[2-(toluene-4-sulfonyl)-ethyl]-1,7-dioxa-spiro[5.5]undecan-4-ol 
• 120483-11-6 (2S,4R,6R,8R,9S)-8-Isopropyl-9-methyl-2-[2-(toluene-4-sulfonyl)-ethyl]-1,7-dioxa-spiro[5.5]undecan-4-ol 
• 113116-34-0 (R)-6-Benzyloxy-4-hydroxy-1-((2S,5R,6S)-6-isopropyl-2-methoxy-5-methyl-tetrahydro-pyran-2-yl)-hexan-2-one 
• 113116-34-0 (S)-6-Benzyloxy-4-hydroxy-1-((2S,5R,6S)-6-isopropyl-2-methoxy-5-methyl-tetrahydro-pyran-2-yl)-hexan-2-one 
• 113116-32-8 (10R,11S)-1-Benzyloxy-3-hydroxy-10,12-dimethyl-11-trimethylsilanyloxy-tridecane-5,7-dione 
• 113116-41-9 (2R,6R,8R,9S)-2-(2-Benzyloxy-ethyl)-8-isopropyl-9-methyl-1,7-dioxa-spiro[5.5]undecan-4-one 

Relevant academic research and scientific papers

STEREOCONTROLLED SYNTHESIS OF THE SPIROKETAL UNIT OF 22,23-DIHYDROAVERMECTIN B1b.

A diastereocontrolled synthesis of the spiroketal sub-unit of 22,23-dihydroavermectin B1b has been developed using a formal double condensation at both ends of pentane 2,4-dione 3 with intermediate formation of the ketal 5.

Total synthesis of avermectins Part 2: Enantioselective synthesis of the C10-C25 northern fragment and final steps for the construction of the 22,23-dihydroavermectin B1b aglycone

The total synthesis of the aglycone of 22,23-dihydroavermectin B1b involves a retrosynthetic two building-blocks approach.A Stille Pd(0) catalyzed cross-coupling reaction is carried out between a northern C10-C25 E-vinylstannane and a southern C1-C9 vinyl iodide.The final steps include successive removal of the carboxyl β-(trimethylsilyl)ethyl protecting group of the intermediate secoester, macrolactonization under Yonemitsu's conditions and removal of the 5-O-TBS protecting group.These last steps have been carried out with the aid of a relay study from commercial Ivermectin; a macrolactone opening reaction of the aglycone in the presence of Ti(OiPr)4 has been developed where the crucial Δ3,4 double bond as well as the configuration at C-2 were totally preserved. - Key words: avermectin / spiroketal / diastereoselection / aldolization / sulfone / homoaldolization / Hoppe reaction / hydrostannylation / palladium Stille coupling / titanium isopropoxide / transesterification / macrolactone / total synthesis