1024796-33-5

Upstream product

• 98844-05-4 3-hydroxy-1-methyl-3-(1-methyl-2-oxo-2-phenylethyl)-1,3-dihydro-2H-indol-2-one 
• 2058-74-4 1-methyl-1H-indole-2,3-dione 
• 58807-96-8 (3E)-3-ethylidene-1-methyl-1,3-dihydro-2H-indol-2-one 
• 182316-18-3 (5S)-5,6-dihydro-5-phenyl-2H-1,4-oxazin-2-one-N-oxide 

Downstream Products

• 1024796-29-9 (3S,3'R,3a'S,7'S)-1,3'-dimethyl-7'-phenyl-6',7'-dihydro-3'H-spiro[indole-3,2'-isoxazolo[3,2-c][1,4]oxazine]-2,4'(1H,3a'H)-dione 
• 58807-96-8 (3E)-3-ethylidene-1-methyl-1,3-dihydro-2H-indol-2-one 

Relevant academic research and scientific papers

Total synthesis of maremycins A and D1 using chiral and cyclic nitrone with (E)-3-ethylidene-1-methylindolin-2-one

Total syntheses of maremycin A (4) and maremycin D1 (8) were described, featuring 1,3-dipolar cycloaddition of a chiral cyclic nitrone 15 with (E)-3-ethylidene-1-methylindolin-2-one (13). The cycloaddition was reversible, especially at high temperature in the presence of a Lewis acid or in a solvent possessing a high acceptor number. One of the cycloadducts was efficiently led to maremycin A (4) and maremycin D1 (8). High optical purity of 4 was confirmed by chiral HPLC comparison with ent-4 prepared from ent-15 and 13.

Synthesis of maremycins A and D1 via cycloaddition of a nitrone with (E)-3-ethylidene-1-methylindolin-2-one

A concise synthesis of maremycins A and D1 has been accomplished via cycloaddition of a chiral cyclic nitrone with (E)-3-ethylidene-1- methylindolin-2-one as a key step. This synthesis clarifies the stereochemistry of the maremycins and is suitable for large-scale synthesis for biological screening.