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 Method 6: 3-Methylene-β-lactones by Dimerization of Monoalkylketenes

DOI: 10.1055/sos-SD-023-00535

Tidwell, T. T.Science of Synthesis, (200623601.

Racemic alkylketene dimers 178 are prepared in situ by quinuclidine hydrochloride induced dimerization of monoalkylketenes generated by dehydrochlorination of alkanoyl chlorides.[‌118‌] The dimers 178 undergo epoxidation upon reaction with dimethyldioxirane forming diastereomeric spiroepoxy-β-lactones 179A and 179B with a strong preference for oxygenation of the face of the double bond opposite to the substituent at C2 (Scheme 57).[‌118‌] The spiroepoxy-β-lactones 179 undergo ring opening with a variety of nucleophiles, and have considerable promise for synthetic applications.

Meeeee 88 8-Meeeeeeee-β-eeeeeeee ee Meeeeeeeeeee ee Meeeeeeeeeee eee Meeeeeeeee Meeeeeeee ee Meeeeeeeee-β-eeeeeeee[‌888‌]

Meeeeeeeeee 88

M8 Meeee (888M/888M) Meeeee (%) ee 888M eee 888M Mee
Me 88:8 88 [‌888‌]
MM8Me 88:8 88 [‌888‌]
Me 88:8 88 [‌888‌]
(MM8)8MMMMM 88:8 88 [‌888‌]
(MM8)8M8 88:8 88 [‌888‌]

e Meee 888.

Meeeeeeee ee eeeeeeeee eee eee eeeeeeeeeeeeeee eeeeeeeeeeee ee eeeeeeeeeeee (8) ee eeee eee eeeeeeeeeeeee eee eeeee eeee eeeeee eeeeeeeeeeee ee eee eeeeeee eee ee eeeeeeee ee e eeee eeeee ee eeeeeeeeeee eeeeee ee eee eeeeeeee (Meeeee 88).[‌88‌]

Meeeee 88 Meeeeeeeeeeeeee Meeeeeeeeeee ee Meeeeeeeeeee[‌88‌]

Meeeeeeeeee 88

Meeeeeee Meeeee ee (%) Mee
eeeeeeeee M 88 [‌88‌]
8-M-eeeeeeeeeeeeeeeeee M 88 [‌88‌]
8-M-(eeeeeeeeeeeeee)eeeeeeeee M 88 [‌88‌]
eeeeeee M 88 [‌88‌]
8-M-eeeeeeeeeeeeeeee M 88 [‌88‌]
8-M-(eeeeeeeeeeeeee)eeeeeee M 88 [‌88‌]

Meeeeeeee ee eeeeeeeee eeeeeeee eeee eeeeeeeeeeeeeeeeeeeee eee 8eee% ee 8-M-(eeeeeeeeeeeeee)eeeeeee ee eeeeeeee ee eeeeeeeeeeeeeee ee eeee eeeeeeeeeee eeeee e 88% eeeee ee eee M-eeeee ee eeeeeeeeeeee 888 (M8=Me), eeeeeeee ee eee β-eee eeeee 888 eeeee eeeeeeee eeee M-eeeeeeeeeeeeeeeeee (Meeeee 88).[‌88‌] Meeeeee eeeeeee eeee eeee eeeeeeeeeeee eeeeeeeee ee eeee eeeeeeeeeee, eee eeee eee eeeeee eeeeee eeeeeee ee eeee eee eeeee. Meeeeeeeeeee eeeeeeeee eeeeeeeee eeee eeeeeeeee eeeeeeeee eeeee eee eeee eeeeeeeeeee eee eeeee eeeeeeeee, eeeeeeeeee eee eeeeeeeeeeee eeeeeeee eee eeeeeeeee ee eeeeee eee eee eeeeeeeee eeeeeeee. Meeeee ee eeeeeee eeeee eeeeeee eee ee eeeeeeeee eeeeeeee ee 8888% eeeeee, eee 8888% ee (Meeeee 88).[‌88‌]

Meeeeeeeeeee eee eeeeeeeeeeeeeee eeeeeeeeeeee eee eeee ee eeeeeeeee ee eeeeeeeee ee eeeeeeeee eeeeeeeee (eee Meeeeee[‌88‌] ee eeeeeeeeeeeeee ee 8-eeeeeeeeeeeeee eeeeeee eeee eeee (eee Meeeeee[‌88‌,‌88‌]

Meeeee 88 8-Meeeeeeee-β-eeeeeeee ee Meeeeeeeee Meeeeeeeeeee ee Meeeeeeeeeee[‌88‌]

Meeeeeeeeee 88

M8 ee (%) ee 888 Meeee (%) ee 888 Mee
Me 88 88 [‌88‌]
Me 88 88 [‌88‌]
eMe 88 88 [‌88‌]
e-Me 88 88 [‌88‌]
MM8MMe8e 88 88 [‌88‌]
MM8MM8Me 88 88 [‌88‌]

e Me8=8,8,8-eMe8M8M8.

Meeeeeeeeeee Meeeeeeee

8-[8-(Meeeeeeeeeeeeeeeee)eeeee]-8-[8-(eeeeeeeeeeeeeeeeee)eeeeeeeeeee]eeeeee-8-eee [888, M8=(MM8)8MMMMM]; Meeeeee Meeeeeeee:[‌888‌]

8-(Meeeeeeeeeeeeeeeee)eeeeeeee eeeeeeee (8.88eeee) ee MM8Me8 (88eM) eee eeeee eeeeee ee e eeee ee eeeeeeeeeeee eeeeeeeeeeeee (8.88eeee) eee eMe8MMe (8.88eeee) ee MM8Me8 (88eM) ee 88°M. Mee eeee eee eeeeee eeeeee ee 88°M eeee 8e, eee eeeeeeeeeeee ee e eeeee ee eee eeeeee. Mee eeeee eeeee eeee eeeeeeeeeeee ee eee eeeeeeee ee eeeeeee (88eM). Mee eeee eee eeeeeeee, eeeeeeeeeeee, eee eeeeeeee ee eeeeee eeeeeeeeeeeeee ee eeee eee eeeeeee ee e eeeeeeeee eee; eeeee: 888ee (88%).