Table 1. Condensation of 4-Methyl Acetophenone (2a) with Sugar Aldehyde 1 in Various Solvents at 25 °C in the Presence of Different Bases and Reaction Times Ranging from 2 to 24 h^a.

entry	solventb	base	reaction time (h)	glucalpropenone 3a (% yield)c	glucal aldehyde 4 (% yield)c
1	EtOH	DBU‡	6	25	50
2	MeOH	NaOMe‡	3	30	50
3	DCM	Pyrolidine‡	3	0	75
4	EtOH	Piperidine‡	24	0	75
5	MeOH	NEt3-proline‡ (1:1)	24	0	78
6	EtOH	Ba(OH)2¶	8	65	0
7	EtOH	KOH¶	2	75	0
8	EtOH	LiOH¶	3	70	0
9	EtOH	NaOH¶	2	85	0
10	EtOH/H2O (1:1)	NaOAc‡	24	NR	NR
11	EtOH	NaOH¶	2		92d

^aReaction conditions: Compound 1 (0.181 mmol), 2a (0.181 mmol); ^‡base (1 equiv.); ^¶5% aq. base (1 mL); NR = No reaction.

^bSolvent used (1 mL).

^cIsolated yield.

^dReaction performed without 2a.