131441-50-4

Upstream product

• 135419-83-9 (4S)-5-dehydroxy-3,4-dihydro-5-oxo-4-(phenylselenyl)-7,13-di-O-(trimethylsilyl)avermectin B₁a aglycone 
• 135419-79-3 (1E,3S,4S)-1-bromo-2,4-dimethylhexa-1,5-dien-3-ol 
• 131413-95-1 (1E,3S,4S)-1-bromo-3-(tert-butyldiphenylsilyloxy)-2,4-dimethylhexa-1,5-diene 
• 131413-98-4 <2R(2E,4S,5S),4S,6S,8R(S),9S>-2-<4-hydroxy-3,5-dimethylhepta-2,6-dienyl>-9-methyl-8-(1-methypropyl)-1,7-dioxaspiro<5.5>undec-10-en-4-ol 
• 131414-03-4 (4S,6S)-6-<(tert-butyldiphenylsilyloxy)methyl>-4-methylcyclohex-2-enone 
• 131413-96-2 <2S(2R,4E,6S,7S)>-2-<2-(tert-butyldimethylsilyloxy)-6-(tert-butyldiphenylsilyloxy)-5,7-dimethylnona-4,8-dienyl>oxirane 
• 135419-81-7 <2R(2E,4S,5S),4S,6S,8R(S),9S>-4-(tert-butyldimethylsilyloxy)-2-<4-(tert-butyldimethylsilyloxy)-3,5-dimethylhepta-2,6-dienyl>-9-methyl-8-(1-methypropyl)-1,7-dioxaspiro<5.5>undec-10-en-4-ol 
• 131413-91-7 <2S,3S,4E,6<2R,4S,6S,8R(S),9S>>-3-(tert-butyldimethylsilyloxy)-6-<4-(tert-butyldimethylsilyloxy)-9-methyl-8-(1-methypropyl)-1,7-dioxaspiro<5.5>undec-10-en-2-yl>-2,4-dimethylhex-4-enal 
• 131414-04-5 (1S,2S,3S,5S,6S)-3-<(tert-butyldiphenylsilyloxy)methyl>-5-methyl-2-<1-methylene-3-(phenylthio)propyl>-7-oxabicyclo<4.1.0>heptan-2-ol 
• 135419-91-9 <2RS,3S,4S,5E,7<2R,4S,6S,8R(S),9S>>-4-(tert-butyldimethylsilyloxy)-7-<4-(tert-butyldimethylsilyloxy)-9-methyl-8-(1-methypropyl)-1,7-dioxaspiro<5.5>undec-10-en-2-yl>-3,5-dimethylhept-5-ene-1,2-diol 
• 135419-72-6 (1S,4S,6S)-6-<(tert-butyldiphenylsilyloxy)methyl>-4-methyl-1-<1-methylene-3-(phenylsulphonyl)propyl>cyclohex-2-enol 
• 135419-80-6 <2R(2E,4S,5S),4S,6S,8R(S),9S>-2-<4-(tert-butyldiphenylsilyloxy)-3,5-dimethylhepta-2,6-dienyl>-9-methyl-8-(1-methypropyl)-1,7-dioxaspiro<5.5>undec-10-en-4-ol 
• 135419-73-7 (1S,2S,3S,5S,6S)-3-<(tert-butyldiphenylsilyloxy)methyl>-5-methyl-2-<1-methylene-3-(phenylsulphonyl)propyl>-7-oxabicyclo<4.1.0>heptan-2-ol 
• 135419-75-9 (1S,2S,3R,4S,6S)-6-<(tert-butyldiphenylsilyloxy)methyl>-4-methyl-1-<1-methylene-3-(phenylsulphonyl)propyl>cyclohexane-1,2,3-triol 

Downstream Products

• 65195-55-3 avermectin B₁a 

Relevant academic research and scientific papers

Total Synthesis of the Anthelmintic Macrolide Avermectin B1a

A highly convergent total synthesis of the anthelmintic macrolide avermectin B1a is described.The key features of this synthesis include the introduction of the C(11)-C(15) portion by selective ring opening of a symmetrical 1,4-bis-epoxide 4 followed by reaction with the anion derived from the 3-methyl-2-(1-methylpropyl)-6-phenylsulphonylpyran 3 to afford the 'northern' C(11)-C(25) fragment 39.Coupling of the derived C(11)-C(25) aldehyde unit 42 with a C(1)-C(10) 'southern' fragment 2 was achieved via a novel deconjugative vinyl sulphone anion sequence.Macrolactonisation and subsequent introduction of the 3,4-double bond gave the aglycone portion 51.The oleandrosyloleandrose disaccharide was introduced by a novel silver-mediated coupling between the 5-acetylated aglycone 70 and the thiocarbonylimidazolide 69.Final deacetylation was accomplished using Super-Hydride to give the natural product 1.