0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via Variation 3: Horner–Emmons and Wittig–Horner Alkenations with Phosphonates and Phosphine Oxides

DOI: 10.1055/sos-SD-047-00004

Schobert, R.; Hölzel, C.; Barnickel, B.Science of Synthesis, (20104764.

Horner couplings of phosphine oxides or phosphonates with aldehydes or ketones have been reported to yield trisubstituted alkenes with high stereoselectivity, especially if either the phosphorus reagent or the carbonyl component bear one large substituent, e.g. a heterocycle. For instance, alkene 134, a key intermediate in the synthesis of phorboxazole A, is obtained in 88% yield and with excellent stereoselectivity (E/Z >95:5) from an α-methyl oxophosphonate and a carbaldehyde (Scheme 46).[‌472‌] Conversely, in syntheses of epothilone A, methyl ketones and α-hetaryl-substituted phosphonates[‌17‌] or phosphine oxides[‌16‌] have been employed to prepare exclusively the E-isomers of the trisubstituted alkenes 135 or 136, respectively (Scheme 46). The HornerEmmons alkenation to produce a trisubstituted E-alkene moiety has even been used as a macrocyclization method in the synthesis of the macrolide antibiotic filipin.[‌473‌]

Meeeee 88 Meeeeeeeeeeeee M-Meeeeee eeee Meeeeeeeeeee eee Meeeeeeee Meeeee[‌88‌,‌88‌,‌888‌]

M eeeeeee-eeeeeeeeeee MeeeeeMeeeee eeeeeeeee ee eeeeeeeeeeeeeeeee eeeeeee eeeeeeeeeeeeee eeeeeee 888 eee 888 eee eeee eeeeeeeee. Me ee eeeee eeee eee eeeeeeeee ee eee eeeeeeee eeeeeeeeeeeee eeeeeeeeeeee β-eeeeeeeeeeeeeeee eeeeee 888/888 eee eeeee eeeeeeeeee eeeeeeeeeeeeee eeee-eeeeeee eeeeeeeeeee ee eeeeeeeeeeeeeeeeeee.[‌888‌,‌888‌,‌888‌] Me eee eeeeeeeee ee eee eeeeeeeeeeeee 888/888 ee eee eeeeeeeeeee eeeeeeeeeeeeeee eee eeeeeeeeeee eeee eeeeeee eeeeeee eeeeeeee, eeee eeeeeeee ee eeeeee, eee ee eeee eeeeee ee eeee eeeeeeeeee eee eeeeeeeeeee eee eeeeee eeeeeeeeee eeeeeeee eeeeeeeee (Meeeee 88). Meeeee eeeeeeeeeeeee eee eeee eeeeeeeee ee eeeeee eeeeeeeeeee eeeeeeeeeeeee ee eeeeeeeeeeee eeeeeeeee eeeeee ee eeeeeeee ee e eeeee eeeeeee eeeeeeeee eeeeeeeee eeeeee eeee ee eeeeeeeeee eeeeeeeeeee eeeeee ee eee β-eeeeee eeee.[‌888‌]

Meeeee 88 Meeeeeeeeeeeee M- ee M-Meeeeee eeee Meeeeeeeeeeee β-Meeeeeeeeeeeeeee Meeeee[‌888‌,‌888‌]

Meeeeeeeeee 88

M8 M8 M8 Meeee (888M/888M) Meeee (%) Mee
Me (MM8)8Me Me 88:88 88 [‌888‌]
Me Me MMe 88:88 88 [‌888‌]

M eeeeeeeeeeeeeee eeee-eeee MeeeeeMeeeee eeeeeeeee ee eeeeeeeeeeeeee eeeeeee eee eeeeeeeeeeeee β-eeeeeee eeeeeeeeeeeeeeee eee eeee eeeeeeee.[‌888‌] Mee eeeeee ee eeeeeeeee eeee eee eeeee eeeeeee ee eeeeeeeeeeeeeeee, eeee ee 888, e eeeeeeeeee eeee eeeee, eee ee eeeee eeeeee (Meeeee 88). Mee eeeeeeee eeeeeeeee, eeee ee 888, eeee eeee ee eeee ee eeeeeee eeee. Meee eee ee eeeeeee eeeeeeee ee e eeeee eeeee eeee 8-(eeee-eeeeeeeeee)-8-eeeeeeeeeeee-8-ee eee eeeeee eee eeeeeeeeee eeeee eeeeeeeee ee ee Meeeeee eeeeeeee, ee ee eeeeee eeeeeeeeeeee eeee ee eeeeeeeeeeeeeee eeeeeeeeee.[‌888‌] Meeeee eee ee eeeeeeee eeee eeeeeee, eeeeeeeee, eee eeeeeeee eeeee eee eeee eeeeeeee M8. Mee eee eeeee eeeee eeeeeeeeeeeeeee 888, eee β-eee eeeeeeeeeee 888 eee eeeeeeee ee eeeeee eeeeee eeee 88% eeee β-eee eeeeeeeeeeeeeeee 888 eee eeee eeeeeeeeeeeeee eeeeee eeeeeee eeee 88:8 (eee M8=8-e-MeM8M8) ee 88:8 (eee M8=8-eeeeeeeee). Meeeeeeeeeeee, eee eeeeeee 888 eee ee eeeeeeeeeee eeeeeee eeeeee eeee eeeeee(MMM) eeeeeeee/eeeeee eeeeeeeeeee ee eeee eeeeeeeeeeee 888M ee eeee eeeeeeeeeeeeeeeeee eeeeeee ee eeee eeeeeeeeeeee 888M ee eee eeeeeee eeeeeee. Meeeeeeee eeeeeeeeeeeeeee eeeeeeeeeeee, eeeee eeeeeeee eee eeeeeeeee ee eeeeeeeeeee ee eeeeeeeeeeeeeee ee eeeee eee eeeeeeeeee eeeeeeeeeeeeee eeeeeee eeeeee (M)-888 (eeee 888M) ee (M)-888 (eeee 888M).

Meeeee 88 Meeeeeeeeeeeee M- ee M-Meeeeee eeee Meeeeeeeeeeee β-Meeeeee Meeeeeeeeeeeeeee[‌888‌]

Meeeeeeeeee 88M

M8 M8 Meeee (%) ee 888 ee ee 888 Meeee (%) ee 888 Mee
(MM8)88Me Me 88 88:8 88 [‌888‌]
Me Me 88 88:8 88 [‌888‌]
8-eeeeeeeee Me 88 88:8 88 [‌888‌]
8-e-MeM8M8 Me 88 88:8 88 [‌888‌]

Meeeeeeeeee 88M

M8 M8 ee ee 888M Meeee (%) ee 888M Meeeee (M/M) ee 888 Meeee (%) ee 888 Mee
(MM8)88Me Me 888:8 88 8:888 88 [‌888‌]
8-e-MeM8M8 Me 88:8 88 8:888 88 [‌888‌]

e Meeeeeeeee ee eeeeeeeee MM.

Meeeeeeeeee 88M

M8 M8 ee ee 888M Meeee (%) ee 888M Meeeee (M/M) ee 888 Meeee (%) ee 888 Mee
Me Me 88:8 88 88:8 88 [‌888‌]
8-eeeeeeeee Me 88:8 88 888:8e 88 [‌888‌]

e Meeeeeeeee ee eeeeeeeee MM.

e Meeeeeeeee ee 8M-MMM (888MMe) eeeeee eeeeeeeeeee.

Meeeeeeeeeee Meeeeeeee

8-(Meeeeeeeeeeeeeeeeee)-8-(8-eeeeeeeeeeeeee-8-eeee)-8-eeeeeeeeee-8-ee-8-ee (888); Meeeeee Meeeeeeee:[‌888‌]

8.8M MeMe ee eeeeee (8.8eM, 8.88eeee) eee eeeee eeeeeeee ee 8°M eeee e eeeeeee ee e eeeeeee MMM (88eM) eeee ee (8-eeeeeeeeee-8-eeee)eeeeeeeeeeeeeeeee eeeee (8.8e, 8.88eeee), eeeeeeee[‌888‌] eeee Me8MMe eee 8-eeeee-8-eeeeeeeee-8-eee. Meeee 88eee, eee eeee eee eeeeeee eee eeeeee ee 88°M, eee e eeee ee eeeeee 8-eeeeeeeeeeeeee-8-eeee eeeeee[‌888‌] (888ee, 8.88eeee) ee MMM (88eM) eee eeeee eeee e eeeeeee. Mee eeee eeeeee eeee eee eeeeeee ee eeee ee ee, eee M8M (88eM) eee eeeee. Mee MMM eee eeeeeee eeeee eeeeeee eeeeeeee, eee eeeeeee eeeeeee eee eeeeeee eeee eeeee (88eM), eee eee eeeeeee eee eeeeeeeee eeee MM8Me8 (8 × 88eM). Mee eeeeeeee eeeeeee eeeeeeee eeee eeeee (MeMM8) eee eee eeeeeeee eeee eeeeeeeeee ee eeee eee eeeeeee ee e eeeeeee ee eeeeeeeeeeeee. Mee eeeee ee eeeeeeeeeeeee eeee eeeeeeeee ee eeeee eeeeeeeeeeeeee (MeMMe eeee eeeeeee). Mee eeeeeee eeee, eeeee eeeeee eeeee, eee eeeeeeee ee e eeeeeeeee eeeeeeeee eeeee; eeeee: 8.8e (88%). Meeeeeeeeeeeeeeee [MeMMe/eeeeeeeee eeeee (ee 8888°M)] eeee eeeeeee ee eee (8M*,8M*)-eeeeee 888M; ee 888888°M. Mee eeeeee, eee eeeee eeee 888M, eee ee eee; eeeee: 888ee (8%); Me 8.88 (MeMMe).

8-Meeeee-8-[(8M)-8-eeeeeeeeeee-8,8-eeee-8-ee]eeeeeeeeeee (888M); Meeeeee Meeeeeeee:[‌888‌]

MeM (88% eeeeeeeeee ee eee; 88ee, 8.888eeee) eee eeeee ee eee eeeeeee ee e eeeeeee eeee ee eee eeeeeee eeee ee eeeeeee ee 888M (888ee, 8.888eeee) ee eeeee MMM (88eM). Mee eeeee eeee eee eeeeeee ee 88°M eee 8e eee eeee eeeeee, eee M8M (88eM) eee eeeee. Mee eeeeeee eee eeeeeee eeee eeeee (88eM) eee eeeeeeeee eeee Me8M (8 × 88eM). Mee eeeeeeee eeeeeee eeeeeeee eeee eeeeee eeee M8M (8 × 88eM), eeeee (MeMM8), eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meee-ee-eeee (Meeeeeeee) eeeeeeeeeeee eeee eee eeeeeee 888M ee e eeeeeeeee eeeeee eeee e eeeee eee eeeeeee eeee; eeeee: 88ee (88%).[‌888‌]