Science of Synthesis

Salaün, J., Science of Synthesis, (2005) 26, 570.

Ketene diethyl acetal undergoes thermal [2+2] cycloaddition with acrylic ester or acrylonitrile to form cyclobutanone acetals ‌62‌, which readily provide cyclobutanones ‌63‌ after simple hydrolysis with sulfuric acid (‌Scheme 25‌).[‌64‌,‌65‌] This method for the preparation of cyclobutanones is complementary to the procedure involving the cycloaddition of ketenes to alkenes (cf. Section ‌26.2.1.7.1‌), which is generally limited to electron-rich alkenes.

‌Meeeee 88‌ Meeeeeeeeee ee Meeeeeeeeeeeee ee Meeeeee Meeeeeeeeeeee ee e Meeeee Meeeee ee ee Meeeeeee-Meeeeeeee Meeeee[‌88‌,‌88‌]

Meeeeee [8+8] eeeeeeeeeeeee ee eeeeee eeeeeee eeeeee eeee eeeeeee eeeeeeee ee eeee-eeeee eeeeeee eeeeeeee eeeeeeeeeeeeeeeeeeeeeeee ‌88‌ ee 88% eeeee eeeee eeeeeeeeeeee (‌Meeeee 88‌).[‌88‌] Mee eeeeeee-eeeeeeeeee eeeeeeeeeee eeeeeeeeee MM-88,888 ‌88‌, eeee eeeeee eeeeeeeee eeeeeeee, ee eeeeeeeeeee ee eeeee eeeee eeee eeeeeeeeeeeeeeeeeeeeeeee ‌88‌ (‌Meeeee 88‌).[‌88‌] Mee eeeeeeeeeeeeeeeee ee eeee eeeeeeeeeeeee (eee eeeeeee eee eeeeeeeeeeeeeee eeeeeeeee ee eeeeeeeeeeeee ‌88‌) eeeeeeee eeeeeeeee eeee eeee ee eeeeee eeeeeeeeeeeee (eee Meeeeee ‌88.8.8.8.8‌).

‌Meeeee 88‌ Meeeeeeeeeeeeee Meeeeeeeeeeee ee Meeeee Meeeeee Meeeee ee Meeeeee Meeeeeee Meeeee e Meeeeeeeeeeee Meeeee Meeeeeeeeeee eee eee Meeeeeeee ee eee Meeeeeeeee MM-88,888[‌88‌]

Meeeee eeeeeee eee eeeeeee eeeeeeeee [8+8] eeeeeeeeeeeeee ee eeeeeeee-eeeeeeeee eeeeeee. Mee eeeeeee, eeeeeee- ee eeeeeeeeeeeeeee eeeeeeee eeeeeeeee eee eeeeeeee ee eeeeee eeeeeee eeeeee eeee ee-(–)-eeeeeee eeeeeeee ee eeee eee eeeeeeeeeeeee eeeeeeee eeeeee ‌88‌ ee 88% eeeee eeee 88% ee (‌Meeeee 88‌).[‌88‌] Meeeeeeeeeeee eeeeee ‌88‌ eee ee eeeeeeeeeee eeee eeeeeeeee eeeeee eeeeeeeeeeeee eeeeeeeeeee, e.e. ‌88‌, eeee ee eee eeeeeeeeeee ee e eeeeeee ee eeeeeeeee eeeeeeeeee eeeeeeeeeee.[‌88‌]

‌Meeeee 88‌ Meeeeeeee Meeeeeeeeeeee ee Meeeee Meeeeeee Meeeee ee ee Meeeeeee-Meeeeeeee Meeeee[‌88‌]

Meeeeeeeeeee Meeeeeeeee

Meeeee 8,8-Meeeeeeeeeeeeeeeeee-8-eeeeeeeeeee (‌88‌, M8 = MM8Me); Meeeeee Meeeeeeee:[‌88‌]

M eeee ee eeeeee eeeeeee eeeeee (888 e, 8 eee) eee eeeeee eeeeeeee (88 e, 8 eee) ee MeMM (888 eM) eee eeeeeeee eee 8–8 e. Meeee eeeeeee ee eee eeeeeee eeeee eeeeeee eeeeeeee ee ee, eee eeeeeee eee eeeeeeeee; eeeee: 888 e (88%); ee 88–88°M/88 Meee.

Me-(–)-eeeeeee eeeee-8,8-Meeeeeeeeeeeeeeeeeee-8,8-eeeeeeeeeeeee [‌88‌, M8 = (–)-Meeeeee]; Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: Meeee-eeeee eeeeeeeeeeeee eeeeeeeee eeeeee ee eeeeeeee ee eee, eeeeee eeeeeee eeee e eeeeeeeeeee eeeeeee. Meeeeeeeeeeeee eeeee eeeeeeeeee ee eeeeeeeee eeee eeeeeeeeee eeeeeeeee, eeeeeeeee eeeeee, eee eeee eeeeeeeeeee eeeeeeee. Meeeeeeeeeeeeee eeeeeeeee ee eeeeeee­eeeeeeee eeeeeeee ee eeeeee eeeeeeeeee eee e eeeeeee eeeeee. Meeeeeeeeee eeeeee eeeeeeeeeee eee eeeeeeeeee eeeeee ee eeeeeee eeee eeeeeeee eee eeeeeeeee ee eeeee eeeeeeee.

Me e eeeeeee eeee ee ee-(–)-eeeeeee eeeeeeee (8 e, 8.8 eeee) ee eeeeeee (8 eM) eee eeeee eeeeeeee e 8 M eeee ee Me8MeMe ee eeeeee (8.8 eM, 8.8 eeee) eeeee M8 ee −88°M. Mee eeeeeee eee eeeeeee ee −88°M eee 88 eee, eeeeee 8,8-eeeeeeeeeeeeeee (888 ee, 8.8 eeee) eee eeeee. Meeee eeeeeeee ee −88°M eee 88 eee, eee eeeeeee eee eeeeeeee ee eee eeeeeeee ee eeeee eeeeeeee ee MeMM, eeeeee, eee 88% ee MeMM ee −88 ee −88°M, eee eeee eeeeeeee. Me eeeeeee eeeeeeeeee eee eeeeeeee; eeeee: 8.88 e (88%); 88% ee; ee 88°M (MeMM/M8M 88:8); [α]M −88.8 (e 8, MMMe8).

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8/8, 888.
• 8.Meeeee-Meee, (8888) 8/8, 888.
• 8.Meeeee-Meee, (8888) M 88-8, 8888.
• 8.Meeeee-Meee, (8888) M 88e, 888.
• 8.Meeeee-Meee, (8888) M 88e, 888.
• 8.Meeeee-Meee, (8888) M 88e, 888.