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Please login or sign up for a free trial to access the full content. Variation 4: From Alcohols and Alkylating Agents

DOI: 10.1055/sos-SD-029-00368

von Angerer, S.; Warriner, S. L.Science of Synthesis, (200729334.

An alternative route to acetals 34 involves alkylation of the hemiacetals. This procedure only works well with aldehydes that readily form hemiacetals, e.g. aliphatic aldehydes, benzaldehyde, and aromatic aldehydes with electron-withdrawing substituents, along with cyclic hemiacetals. Appropriate alkylating agents are the adducts 33 formed by dimethyl or diethyl sulfate with dimethylformamide (Scheme 42).[‌291‌,‌292‌] Aliphatic α,β-unsaturated aldehydes also add the alcohol across the C=C bond, giving the corresponding 3-alkoxy acetals in good yield.[‌292‌] Among the ketones investigated, only cyclohexanone gives reasonable yields of the dimethyl (74%) and diethyl (62%) acetals.[‌292‌]

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Meeeeeeeeee 88

M8 M8 Meeeee Meee (e) Meeee (%) Mee
Me Me M 8 88 [‌888‌]
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8-MeM8M8 Me M 88 88 [‌888‌]
MM=MMMe Me M 88 88 [‌888‌]

Mee eeeeeeee ee eeeeeeee eeeeeeeee eeee eeeeeeee ee eeee eeeeeee eeee ee 88 eee 88 eee ee eeeeeeeee eeeeeeee eeeee eeeeeeee eeeeeeeeee, eeee eeeeeeee eeeeeee ee eee eeeeeeeeee eeeee. Meeeeeeee eeee eeeeeeee-eeeeeeeeeee eeeeee eeeee ee eeee eeeeeeeeeee eeee eeeeeeee eeeeeee eeeee eee eeeeeee eee eeee eeeee ee eeeeee eeeeeeeee eeeeeeee (Meeeee 88),[‌888‌] eeeeeee eeeee eeeeeeeee eeee ee ee eeeeee eee eeee eeeeee ee eeee eeeee ee eee eeeeeeee ee eee eeee.[‌888‌]

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Meeeeeeeeeee Meeeeeeee

Meeeeee 88; Meeeeee Meeeeeeee:[‌888‌,‌888‌]

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Meeeeee 88 eee 88; Meeeeee Meeeeeeee:[‌888‌]

MMMMMMM: Meeeeeee eeeeeee ee eeeeeeeee eee eeeeeeeeee ee eee eeee, eeee, eee eeeeeeeeeee eeeeee eee ee e eeeeeeee eeeee eeeeeeeeee.

M eeee ee eee eeeeeeee (8e) ee MeMM (8888eM) eee eeeee eeee eee eeeeeeeeee eeeeee ee Me8MM8 (8.8e eee eeeeeeeeeeeeeeeeee eee 88.8e eee eeeeeeeeeeeeeeeeee). Meee 88eee eee eeee eee eeeee eeeeeeee ee 8M ee MeMM (8.88.8eee eee eee Me8MM8), eeee eeeeeeee eee eee eeeeeee. Meeee eee eeeeeeee, eee eeeeeee eee eeeeeeee eee 88eee. Meeee eeeeeee ee ee, eee eeeeeee eee eeeeeeeee eeee Me8M. Meeee eeeeeeeeeee ee eee Me8M, eee eeeeeee eee eeeeeee eeee e eeee ee MM8MMMMe ee eee MeMM eee eeee eeeeeeeee eeee Me8M. Mee eeeeeee eeeee eee eeeeeeeee eeeeeee eeeee eeee eee MeMM. Mee eeeeeeee eeeeeee eeeeee eeee eeeeeeeee eeee Me8M eee eee eeeeeeee eeeeeee eeeee eeee eeeee (M8MM8). Meeee eeeeeeeeeee ee eee eeeeeee, eee eeeeeee eee eeeeeeee ee eeeeeeeeeeee eeeee eeeeeee eeeeeeee; eeeee: 8888%.

8-Meeeee-8-(eeee-8-eeeeeee)eeeeeeeeeeeeeee (88):[‌888‌]

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