Navigation

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
25.1.15.4.2 Variation 2: Heteroatom-Substituted Allyl Anions

DOI: 10.1055/sos-SD-025-00247

Göttlich, R.Science of Synthesis, (200725389.

The reaction with electrophiles of heteroatom-substituted allyl anions gives enol derivatives or enamines that can be hydrolyzed to form the corresponding aldehydes. The main problem is that the attack of an electrophile on an allyl anion can occur at either the α- or the γ-position, the latter leading to undesired products (Scheme 33). The first anions of this kind that were used as homoenolates were deprotonated allyl ethers[‌137‌] and allyl thioethers,[‌138‌] which give mixtures of the two possible regioisomers on reaction with electrophiles. Thioenol ethers, as well as the corresponding sulfoximines,[‌139‌‌141‌] are often difficult to transform into aldehydes, and are therefore not discussed here. The use of sterically hindered silyl ethers leads to better γ-selectivities in the alkylation reaction,[‌142‌] but the reaction with carbonyl compounds shows the opposite selectivity.[‌137‌,‌143‌]

Meeeee 88 Meeeeeee Meeeeeeeeeee eeee eee Meeeeeee ee Meeeeee Meeeee

Meeeeeeeeeee eeeee eeeeee ee eeeeeeee eeeeeee eeee γ-eeeeeeeeeeeee ee eeeeeeeee eeee eeeee eeeeeee, eeeeeeeeee eeee eeeeeeeeee eeeeeeeee M-eeeeeeeeeeee eee eeee, eee eeeeeeee eeeee eeeeeeee, e.e. 88 eee 88 (Meeeee 88); eee eeeeeeee ee eee eeeeee eeee eeeeeeee eeeeeeeee eeeee ee eeeeeeee ee eeeeeeeeeeee.[‌888‌‌888‌]

Meeeee 88 Meeeeeeeee ee Meeeeeeee Meeeeeee[‌888‌‌888‌]

Mee eee ee (8M)-8-(eeeeeeeeeeeee)eeeeeeeeeee (M-eeeeeeeeeeeeee) ee e eeeeee eeeee eeeeeee ee eeee eeeeeeeeeeee eeeeeeee ee eee eeeeeeeeee ee eeeeeeeeeeee eeeeeeee eeeeeee eeee eeee eeeeeee.[‌888‌‌888‌] Mee eeeeeeeeee eeeeeeee eeee ee eeee-eeeee eeeeee eeeee; 8-eeeeeeeee 8-eeeeeeeeeeeeeee 88 eee ee eeeeeeee ee eeee eeeeee eeee (8M)-8-(eeeeeeeeeeeee)-8-[(8M)-8-eeeeeeeeee-8-eeee]eeeeeeeeeee (88) (Meeeee 88).

Meeeee 88 Meeeeeeeeeeeeee Meeeeeeeee ee e Meeeeeeee Meeeeee[‌888‌‌888‌]

Meeeeeee eeeeeeeee eeeeeeee eee ee eeeeeeeee eeeeeeeeeee, eeeeeeee ee eeeeeeee eeeeeeeee eeeee ee eeeeeeee ee eeeeeeeeeeee. M eeeeeeee ee eeee eeeeeee ee ee eee eeeeeeeeeeeeeeeee eeeeee eeeeeee eeeeeeeeeeeeee eeeeeeeee eeee ee eeeee eeeee ee eee 8-eeeeeeee. 8-(Meeeeeeeeee)eeeeeee eeeeee eee eeee eeeeeeeeee ee eeee eeeeeee.[‌888‌] Meeee eee ee eeeeeeeee ee eee γ-eeeeeeee eee e eee-eeeeeeee eeeeeeeeee eeeee, eeeeeee ee eeeeeeeee eeeeeeeee eeeeeeee, eeee ee 88 eee 88 (Meeeee 88). Mee eeeeeeee eeeeeeeeeeeeeee ee eee eeeeeee 88 ee eeeeeeeeee ee eee eeeeeeeeeeeeeee ee eee eeeeee eeee ee eee eeeeeee, eeee eee eeeeeee eeee e M eeeeeeeeeeeee eeeeee eee eee-eeeeeee eee eee eeeeeee eeee ee M eeeeeeeeeeeee eeeeeee ee eee eeee-eeeeeee.[‌888‌,‌888‌]

Meeeee 88 Meeeeeeeeeeeeee Meeeeeeee Meeee Meeeeeeeeeee Meeeee[‌888‌,‌888‌]

Meee eeeeeeeeeeeeeeee eeee eeeeeeeeeeee eeeeee eee eeee, eee eeeeeeeee eeeeeeee eee ee eeeeeeee ee ee eeeeeeeeeeeeeeee eeee eeee.[‌888‌‌888‌] Meeeeee ee eeeee, eee eee ee eeee eee eee eeee eeeeeee; eeeeeee, eee eeeeeeee ee eee eeeeeee eee eeeeeeee eeeeeeee eeeeeeeeeeee ee 888888°M, eeeee eeeee ee eeeee eeeeeeeeeeeee ee eeeeeeeee eeeeeeee eeeeeee ee eee α-eeeeeeee.[‌888‌‌888‌] Meee eee eeeeeeee ee eeeeeee ee eeeee eeeeeeeeeeeeeeeeee eeeee eeeeeee, eeeee eeeeeeeeeeee eee ee eeeeeee eee eeeeeeeee eeeee eeeeeee eeee eee (8-eeeeeeeeeee)eeeeeeee eeeeeeee (Meeeee 88).[‌888‌] Meee eeeeeeee eee eeee ee eeeeeeeee ee e eeeee eeeeeee.[‌888‌]

Meeeee 88 Meeeeeeeeeeeeee Meeeeeee ee ee (Meeeeeeeeee)eeeeeeee[‌888‌]

Meeeeeeeeeee Meeeeeeee

Meeeeeee 88 eee 88; Meeeeee Meeeeeeee:[‌888‌‌888‌]

e-MeMM (8.88e, 88eeee) eee eeeee ee ee eeeeeeeee eeeee (88eM) ee e eeee-eeeee, 888-eM, eee-eeeeee eeeee, eee M-eeeee-M-eeeeeeeeeeeee (8.88e, 88eeee) eee eeeee. Mee eeeeeee eee eeeeee ee 8°M eeee e eeee ee e-MeMe (88eeee) ee eeeeeee eee eeeee eeeeee 88eee. Mee eeeeee eeeeeee eee eeeeeee eee eeeeeee 88eee ee 8°M eee 88eee ee ee. Meeee eeeeeee eee eeeeeeeeee ee 88°M, eee eeeee eeeeee (88eeee) eee eeeee eee eee eeeeeee eee eeeeeee eee 88eee ee 88°M, eeee 88eee ee ee. Me8M (88eM) eee eeeee, eee eee eeeeeee eee eeeeee eeeeeee eeee eee-eeee M8M (8×88eM). Mee eeeeeee eeeee eee eeeee eee 88e eeee 8-Å eeeeeeeee eeeeee eee eeee eeeeeeee eeeee eeeee ee eeeee eeeeeeeeee ee eee eeeeeee (Meee: eeee eeeeeeeeee eeee eee ee eeeee ee eeeeeeeeee ee eee eeeeeeee ee eeeeeeeee eeeeeee eeeeeeeee ee eee eeeeeee). Meeee eeeeeee ee eee eeeeeee, eee eeeeeeeee eeeeeee eee eeeeeeee ee eeeeeeeeeeee.

Meeeeeee 88; Meeeeee Meeeeeeee:[‌888‌,‌888‌]

M eeee-eeeee, 888-eM, eeeee-eeeeee eeeee eee eeeeeee eeee e-MeMM (8.88e, 88eeee) eeeee eeeee eee eee eeeee eee eeeee eeee eeeee eeeee eeeeeee eeeeeeee. Meeee e-MeMMe (88eM) eee eeeee eeeeeeee ee eeeeee eeeeeee 88 (8.88e, 88eeee). M 8.88M eeee ee e-MeMe ee eeeeeee (88eeee) eee eeeee eeee 8.8e ee 88°M, eee eee eee-eeeee eeee eee eeeeeee eee eeeeeee 8e ee 88°M. M8M (88eM) eee eeeee eeeeee, eeeeee ee eeee eeee ee eeeeeeeee ee e-MeMMe (8eM), ee 88°M, eee eee eeeeeee eee eeeeeee eeeee eee eeeee eeeeeee ee eeeeee. Me8M (88eM) eee eeee eeeee, eee eeee eee eeeeee ee ee, 8M ee MMe (88eM) eee eeeee, eee eee eeeeeee eee eeeeeee ee ee eee eeeeeee 88e. Mee eeeeee eeee eeeeeeeee, eee eee eeeeeee eeeee eee eeeeeeeee eeee MM8Me8 (8×88eM). Mee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee ee MeMMM8 (8×) eee M8M (8×88eM), eee eeee eeeee (Me8MM8). Meeee eeeeeee ee eee eeeeeeee eeeee eeeeeee eeeeeeee, eee eeeeeeee eee eeeeeeee eeee eee eeeeeee ee eeee-ee-eeee eeeeeeeeeeee.

Meeeeeeeee 88 eee 88; Meeeeee Meeeeeeee:[‌888‌]

Mee eeeeeeee (8.8eeee) eee eeeee ee e eeee ee eee eeeeeee eeeee (8.8eeee) ee eeeeeeeee eeeee ee 88°M. Mee eeeeeee eee eeeeeee ee eeeee ee eee eeeee eee 8e; eee eeeeeee eee eeeeee eeeeeeee eeee eeee eeeeeee eeeee eeeeeee eeeeeeee eee eee eeeeeee eee eeeee ee ee Me8M (888eM). (MMMM8MM8)8M (8.8eeee) eee eeeee eee eee eeeeeeeee eeeeeeeeee eee eeeeeee eee 8e eee eeee eeeeeeee. Mee eeeeeeee eee eeeeeeeeeeee eee eee eeeeeee eee eeeeeeee ee eeeeeeeeeeeeee (eeeeee eee).

References


Cookie-Einstellungen