TABLE 2.

Condensation reactions of 3 with aldehydes and ketones

		product: yield,a E/Zb
entry	carbonyl	method Ac	method Bd
1		5: 92%, 81/19	5: 97%, 95/5
2		6: 92%, 78/22	6: 87%, 90/10
3		7: 90%, 76/24	7: 59%, 94/6
4		8: 81%, 70/30	8: 95%, 94/6
5		9: 59%, 51/49	9: 81%, 72/28
6		10: 95%, 83/17	10: 98%, 90/10
7		11: 95%, 75/25	11: 92%, 91/9
8		12: 78%, 75/25	12: 78%, 91/9
9		13: 95%, 72/28	13: 96%, 80/20
10		14: 54% (63%e), 80/20	14: 63%, 70/30
11		15: 79% (91%e), 85/15	--
12		--	16: 77%
13		--	17: 88%, E onlyf

^aYields of isolated and purified products.

^bE/Z ratio of diastereomers in the crude reaction mixture was determined by ¹⁹F NMR, prior to isolation. No change in ratio was observed after purification.

^cMethod A: sulfone 3, 2.0–2.5 molar equiv; DBU, 4.0 molar equiv; TBAF, 0.20 molar equiv. For 11 and 13, 3.0 molar equiv of 3 was used. Sulfone was added to solution of aldehyde and base.

^dMethod B for aldehydes: sulfone 3, 2.0 molar equiv; LHMDS, 2.4 molar equiv; TBAF, 2.0 molar equiv. Method B for ketones: sulfone 3, 3.0 molar equiv; LHMDS, 5.0 molar equiv; TBAF, 3.0 molar equiv. LHMDS was added to a solution of sulfone and aldehyde.

^eYield was calculated using octafluoronaphthalene as an internal standard.

^fDetermined by NOESY experiment on the diene obtained by Lindlar reduction of 17 (see Figure 5).