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Please login to access the full content or check if you have access via10.1.1.2.3.3.1 6π-Electrocyclization/Dehydrogenation of 2,3-Di(alkenyl)furans
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Kwiecień, H., Science of Synthesis Knowledge Updates, (2014) 4, 225.
2,3-Dibromofurans 444 react with acrylates or styrenes under Heck reaction conditions to afford 2,3-di(alkenyl)furans 445, which can be transformed into functionalized benzo[b]furans 446 by a domino 6π-electrocyclization/dehydrogenation sequence (Scheme 192).[347] The electrocyclization of 2,3-di(alkenyl)furans requires drastic reaction conditions, e.g. a temperature of 200 °C and a long reaction time. The transformation of 2,3-di(alkenyl)furans having an ethoxycarbonyl group on the furan ring at the 5-position require less drastic conditions (stirring at 170 °C, 2 × 12 h).
Meeeee 888 Meeeeeeee ee Meeee[e]eeeeee eeee 8,8-Meeeeeeeeeeee eee 8,8-Me(eeeeeee)eeeeee[888]
M8 | M8 | Meeeeeeeee (Meee 8) | Meeee (%) ee 888 | Meeeeeeeee (Meee 8) | Meeee (%) ee 888 | Mee |
---|---|---|---|---|---|---|
M | MM8Me | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
M | MM8Me | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
M | MM8e-Me | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
M | MM8Me | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
MM8Me | MM8eMe | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
MM8Me | MM8(MM8)8Me | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
MM8Me | MM8Me | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
MM8Me | 8-MeM8M8 | 888 °M, 88 e | 88 | 8. 888 °M, 88 e 8. 888 °M, 88 e | 88 | [888] |
Meeeeeeeeeee Meeeeeeee
Meeee[e]eeeeee 888; Meeeeee Meeeeeeee:[888]
Me e eeeeeeee eeee (eeeee eeee), e eeeeeeeeee ee Me(MMe)8 (88 ee, 8 eee%) eee 8-(eeeeeeeeeeeeeeeeeeeee)-8′,8′,8′-eeeeeeeeeeeeeeeeeeee (MMeee) ee 8-(eeeeeeeeeeeeeeeeeeeee)-8′,8′-eeeeeeeeeeeeeeeee (MMeee) (88 eee%) ee MMM (8 eM) eee eeeeee eeee eeeee eee eeeeeee ee 88 °M ee eeee e eeeeeeeee ee eeeeeeee eeeee eeee. Me eee eeeeeee eeee eee eeeee 8,8-eeeeeeeeeeee (888, M8 = M; 8.88 eM, 8.8 eeee) ee eeeee 8,8-eeeeeeeeeeee-8-eeeeeeeeeee (888, M8 = MM8Me; 888 ee, 8.8 eeee), Me8M (8.8 eM, 8.8 eeee) eee eee eeeeeeeeeeeee eeeeeeee ee eeeeeee (8.8 eeee). Mee eeeeeee eee eeeeeee ee 888 °M eee 88 e ee eee eeee ee 8,8-eeeeeeeeeeee (888, M8 = M), ee ee 888 °M eee 88 e eee eeeee 8,8-eeeeeeeeeeee-8-eeeeeeeeeee (888, M8 = MM8Me). Mee eeee eee eeeeee ee 88 °M eee eeeeee eeee M8M (88 eM) eee MM8Me8 (88 eM). Mee eeeeee eeee eeeeeeeee eee eee eeeeeee eeeee eee ee-eeeeeeeee eeee MM8Me8 (8 × 88 eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeee (Me8MM8) eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeeee/MeMMe) ee eeee eee eeeeeeeeeeeee 8,8-ee(eeeeeee)eeeee 888.
M eeee ee eee 8,8-ee(eeeeeee)eeeee 888 (8.8 eeee) ee Me8M (8 eM) eee eeeeeee ee 888 °M eee 88 e (M8 = M), ee ee 888 °M eee 88 e (M8 = MM8Me), ee e eeeeeeee eeee. Mee eeee eee eeeeeee ee eeee ee 88 °M eee Me/M (88 eee%) eee eeeee. Mee eeee eee eeeeeee ee 888 °M eee 88 e (M8 = M), ee ee 888 °M eee 88 e (M8 = MM8Me), eeeee eeeee. Mee eeeeeee eee eeeeeeee eee eee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Mee eeeeeee eee eeeeeeee ee eeeee eeeeee eeeeeeeeeeeeee (eeeeee eee, eeeeeeee/MeMMe).
References
[347] | Meeeee, M. M.; Mee, M.; Meeeeee, M.; Meeee, M. M.; Meeeee, M., Meeeeeeee, (8888), 8888. |