Science of Synthesis

Marsden, S. P., Science of Synthesis, (2005) 26, 1080.

Oxophosphoranes such as ‌186‌ are stabilized phosphorus ylides and as such react with aldehydes to deliver enones (e.g., ‌187‌) with E stereochemistry (‌Scheme 36‌).[‌166‌] The relatively nonbasic nature of the reagents means that sensitive compounds such as those susceptible to racemization are tolerated in either the phosphorane (e.g., ‌188‌) or aldehyde (e.g., ‌189‌) components.[‌167‌,‌168‌] Ketones are not generally competent partners in intermolecular Wittig reactions with oxophosphoranes, but highly reactive ketones including α-oxo esters (e.g., ‌190‌)[‌169‌] and fluorinated ketones[‌170‌] do react in useful yield. Trisubstituted enones can also be accessed by reaction of substituted phosphoranes such as ‌191‌ with aldehydes, although the control of the alkene geometry in the resulting enone ‌192‌ is not always assured.[‌171‌] Enones (e.g., ‌193‌) are prepared directly from activated allylic or benzylic alcohols such as 3-bromoprop-2-en-1-ol by a convenient one-pot oxidation/Wittig protocol using manganese(IV) oxide as oxidant.[‌172‌]

‌Meeeee 88‌ Meeeee Meeeeeeee ee Meeeeeeeeeeeeee[‌888‌–‌888‌,‌888‌,‌888‌]

Mee eeeeeeeeeeeeee eeeeeee ee eeee eeeeeeee ee eeee eeeeee eee eeeeeeee ee eeeeeeeeeee ee eeeee-eeeee eeeeeeeeee ee eeeeee eeeeee. M eeeeeeeee eeeeeee ee eeee ee ee eee eeeeeeeee ee eee eeeeeee[8.8.8] eeeeeeee ee eeeeeeee ‌888‌ (‌Meeeee 88‌).[‌888‌] Meeeeeeee eeeeeeeeeeeee eeeeeeeee eeee eeee eeee eeeeeeee eeeeee ee eeeeeeee ee eeee eeeee eeeeeee eeeee eeeeeeeee, eee eee eeee eee eeeeeeeeeeee Meeeee eeeeeeee ee eeeee ‌888‌ eeeee eeeeeeee ee eee eeeeeee. Meeeeeeeeee, eee eee ee e eeeeee eeeeeeeee ee eee eeeeeeeeeee ee eee eeeeeeeeeee ‌888‌ eeeeee eeeeeeeeee eeeeeeeee ee eee Meeeee eeeeeeee, eeee eee ee eee eeeeeeeee eeeeeeee eeeeee eeeeeeee eeeeeeeeeeeeee.[‌888‌]

‌Meeeee 88‌ Meeeeeeeeeeeee Meeeee Meeeeeee ee ee Meeeeeeeeeeeee[‌888‌,‌888‌]

Meeeeeeeeeee Meeeeeeee

(8M,8M)-8-Meeeeeeeee-8,8-eeee-8-eee (‌888‌); Meeeeee Meeeeeeee:[‌888‌]

M eeeeeee ee (M)-8-eeeeeeeee-8-ee-8-ee (88 ee, 8.8 eeee), 8-(eeeeeeeeeeeeeeeeeeeeee­eeee)eeeee-8-eee (8.88 eeee), eee MeM8 (888 ee, 8.88 eeee) ee eee MM8Me8 (8 eM) eee eeeeeee eee 8–8 e eee eeeeeeeee ee MMM eeeee eee eeeeeeee eeeeeeee eee ee eeeeee eeeeeeeeee. Mee MeM8 eee eeeeeee ee eeeeeee eeeeeee e eee ee Meeeee, eeeee eee eeee eeeeee eeee eeeeeeeeee MM8Me8 (88 eM). Mee eeee eee eeeeeeeeeeee ee eeeee 8 eM. Meeeeeeeeeee ee eeeeee eeeeeeeeeeeeee (eeeeee eee, Me8M/eeeeeeeee eeeee) eeee e eeeeeeeee eee; eeeee: 88%.

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) 8/8e, 8888.
• 8.Meeeee-Meee, (8888) M 8, 888.
• 8.Meeeee-Meee, (8888) M 88-8, 8888.
• 8.Meeeee-Meee, (8888) M 88e8, 888.