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Applications of alkyl orthoesters as valuable substrates in organic transformations, focusing on reaction media

“…Similar to the products (474), 2-acetylcyclooctanone derivative (R ¼ Me) resulted in acetal (475) in 86% yield. Finally, 2-acetylcyclopentanone (R ¼ Me) and 2-acetyl cycloheptanone (R ¼ Me) gave rise to acetals (476) and (477) in 75 and 74% yields, respectively. 410 In 1991, the highly enantioselective hydroformylation of vinyl aromatics (478) was reported by the Hegedus group in the presence of TEOF (5).…”

“…Benzo[4,5]imidazo[1,2- c ]-[1,2,5]oxadiazolo[3,4- e ]pyrimidine (584) was obtained via the cyclocondensation of 3-amino-4-(1 H -benzo[ d ]imidazol-2-yl)-1,2,5-oxadiazole (583) with TEOF in boiling acetic anhydride for 12 h, in 60% yield ( Scheme 173 ). 476 …”

“…imidazo[1,2-c]-[1,2,5]oxadiazolo[3,4-e]pyrimidine (584) was obtained via the cyclocondensation of 3-amino-4-(1Hbenzo[d]imidazol-2-yl)-1,2,5-oxadiazole (583) with TEOF in boiling acetic anhydride for 12 h, in 60% yield (Scheme 173) 476. 6-{[(5-Nitrothiophen-2-yl)methylene]amino}-3-phenyl-2-thioxo-2,3-dihydrothiazolo-[4,5-d]-pyrimidin-7(6H)-one (587)477,478 as a brown compound was prepared via the cyclocondensation of thiazoline derivative (586), arising from 5-nitro-2thiophenecarboxaldehyde (585), with TEOF in the presence of acetic anhydride under reux conditions within 3 h in 61% yield (Scheme 174).…”